Category: Science

Introduction

The chemical symbol for flerovium is Fl, and the atomic number of flerovium is 114. Super heavy describes this element’s status as one of the heaviest in the periodic table.

It’s also a highly radioactive substance or component. It wasn’t until 1998, in a Russian research facility, that this element was found.

The p-block is represented by elements in the periodic table by those in group 14, period 7. In its electronic form, flerovium has the formula\(\left[ {{\bf{Rn}}} \right]{\rm{ }}{\bf{5}}{{\bf{f}}^{14}}{\bf{6}}{{\bf{d}}^{10}}{\bf{7}}{{\bf{s}}^2}{\bf{7}}{{\bf{p}}^2}\). Since it is the most massive element in the carbon (C) family, it is a member of that family. Its radioactivity means that only a little amount of this element may ever be produced.

What is Flerovium?

With an atomic number of 114 and the symbol, flerovium is one of the heaviest known elements (Fl). To be specific, this element belongs to the p-block. It is part of period 7 and the 14th group. Then it must be one of the elements of the carbon group. It’s also the heaviest member of the carbon family. As a man-made substance, it is also highly (very) radioactive (does not occur naturally on the surface of the earth).

At the time of its discovery in 1998, the element was given the name flerovium in honour of the flerov laboratory of nuclear reactions in Dubna, Russia (Asia). However, over time, the name was changed to the flerov to honour the Russian physicist Georgy Flyorov. According to estimates, its mass will be 289.

How Scientists Discovered Flerovium Elements?

In 1998, researchers at Russia’s Joint Institute for Nuclear Research in Dubna successfully synthesised flerovium. They pounded plutonium atoms with calcium ions.

One atom of flerovium-289, an isotope with a half-life of around 21 seconds, was created in this process.

What are the Uses of Flerovium?

Due to it being the heaviest element and the radioactive, Flerovium has very few applications. This substance has zero practical applications outside of academic institutions. No biological function is served by it Its formation in nuclear reactors is possible. Very few flerovium atoms have been created or identified so far. Because of its hazardous properties, it is also not used in commercial applications (as it is a radioactive element).

Flerovium Chemical Properties

• Flerovium is the bulky member present in group 14 elements found below lead.
• The chemical behaviour of the element is expected to be very distinctive.
• The 7s orbitals (s, p, d, f…) are very (largely) highly (more) stabilized (stable) in flerovium, therefore a very large \(s{p^3}\) (type) orbital (orbits) hybridization is needed to achieve a +4-oxidation state (O.S.).
• Flerovium is predicted to be more stable (most) than lead (Pb) in its +2-oxidation state while at a +4 (O.S.)-oxidation state it should be highly (very much) unstable.

Physical Properties of Flerovium

Some of the physical properties of Flerovium element are as follows-

• Appearance- Liquid phase at STP (predicted)
• Melting Point (M.P.)- It has a melting point of around 200K or -73 °C or -100 °F.
• Boiling Point (B.P.)- It has a boiling point of around 380K or 107 °C or 224°F.
• Density- It has a density of approximately 9.928 \(g/c{m^3}\).
• Crystal Structure- Flerovium has a face-centred cubic lattice type.

General Properties of The Fl Element

Flerovium is a rarely used heavy material. Its atomic number is 114 and the molar mass is predicted to be 289. It is denoted or represented by the symbol Fl. It is a carbon group element that lies in the p-block of the periodic table. Its colour is predicted (assumed) to be silvery-white, grey, or metallic. Sometimes it is also known as Ununquadio. Flerovium is a radioactive synthetic element with five known isotopes so far. 

Fun Facts About the Fl Element 

• Flerovium is considered a metal due to its high density and it is an extremely radioactive metal.
• This metal or element can be rarely produced in nuclear reactors.
• Its production is very expensive.
• It is obtained by bombarding plutonium ions and calcium.
• It is a p-block element present in the carbon group.

Summary

Flerovium represented or denoted by the symbol (Fl) is one of the heaviest known elements with the atomic number (Z) 114. It is a p-block element. It lies in group 14 and period 7. That means it is a carbon group element. And it is the heavier element in the carbon group and the p-block. It is also an extremely (very much) radioactive man-made element (does not occur naturally on the surface of the earth). At the time of discovery, it was named after (the place where it was produced) flerov laboratory (lab) of nuclear reactions located in Dubna, a place in Russia, where this element (metal) was produced (discovered) in the year 1998. Element is produced by bombarding a target (aim) of plutonium-244 (\(Pu_{94}^{244}\)) with the nuclei (accelerated) of calcium (\(Ca_{20}^{48}\)):

 

Frequently Asked Questions

1. How many isotopes of Flerovium are known?

Ans: Flerovium has seven known isotopes, and possibly 2 nuclear isomers. The longest-lived isotope is \({}^{289}Fl\) with a half-life of 1.9 seconds, but the unconfirmed \({}^{290}Fl\) may have a longer half-life of 19 seconds.

2. Who discovered flerovium and when?

Ans: A team of scientists from JINR (Joint Institute for Nuclear Research), located in Dubna, a place in Russia discovered the flerovium (element) in the year 1998.

3. Write the reaction involved in the formation of flerovium.

Ans: The reaction involved in the formation of flerovium is –

Introduction

Radiation refers to the phenomenon when energy in the form of waves or particles is emitted. This can include alpha particles, beta particles, and even gamma photons. Alpha particles are also referred to as alpha radiation or alpha waves, and they consist of two protons and two neutrons.

What is an Alpha particle?

Alpha particles are produced through the α-decay of certain radioactive elements such as uranium, thorium, radium, and plutonium. They are positively charged and are denoted by the symbol . It is interesting to note that these particles are quite similar to helium nuclei and may even be referred to as doubly ionised helium atom \(H{e^{2 + }}\).

Since these particles carry a double positive charge, they have high ionizing power but do not penetrate too much into matter. When α-decay occurs, the parent element emits an alpha particle, causing it to transform into a different element. For example, uranium-238 undergoes α-decay by emitting α-particles and is transformed into thorium-234.

Since the alpha particle carries two protons and two neutrons, the atomic and amss numbers of the parent are reduced by 2 and 4, respectively.

Mass Of An Alpha Particle

The mass of an alpha particle is the same as that of a Helium atom, and is given as:

Characteristics of Alpha Particles

Fundamental Properties of Alpha Particles

• Their velocities can range from \(1.4 \times {10^7}\;to\;1.7 \times {10^7}m{s^{ – 1}}\)

• They tend not to deviate from a straight line path
• They are highly ionising, typically 100 times as ionising as beta particles and \({10^4}\) times as ionising as gamma rays. They can even ionise biomolecules.
• They have low penetration depth and may even be blocked by a sheet of paper.
• Typically, the penetration power is 1/1000 times that of beta rays and 1/100000 times that of gamma rays.
• They can interact with matter via coulomb forces.
• Alpha particles lose kinetic energy quickly and thus, have short range.
• Due to the charge on them, they are easily deflected by electric and magnetic fields. The positive charge makes them attracted to the negative plates.
• They can produce both fluorescence and phosphorescence.
• These particles can be scattered by heavy elements like gold.
• Alpha particles can cause heating effects and though they can affect photographic plates, the effect is very weak.
• Their mass is roughly four times that of Hydrogen atoms.

Uses of Alpha Radiation

•  Ra-226 has been used to destroy cancerous cells. Due to their low penetration depth, they only affect the malignant cells and leave normal cells unharmed.
• Americium – 241 is an alpha source that is used in smoke detectors. Smoke ionizes it, which causes an electric current, causing the trigger of an alarm.
• Satellites and spacecraft use Plutonium – 238 in their batteries. The heat produced due to alpha decay is converted into other forms of energy.
• Medical pacemakers used to utilize Plutonium – 238 as fuel source but this practice has non  been discontinued.
•  Polonium – 21, an alpha emitter, is used to reduce static in industrial settings. Being positively charged, the alpha particles attract the electrons and reduce chances of static electricity.
• Strontium – 90 is an alpha emitter that is used as a fuel source for oceanic buoys by the U.S coast guards. 

Summary

Alpha particles consist of two protons and two neutrons bound together, which is equivalent to a helium nucleus. They have high ionization power, allowing them to ionize matter easily. 

In nature, alpha particles are emitted from radioactive elements such as U-238 and R-226, and they can also be produced artificially in reactors using radioisotopes like plutonium and californium. These particles have various applications, including cancer treatment, smoke detectors, pacemakers, and thermoelectric generators. The relatively low penetration depth of these particles means that they cannot penetrate the skin and thus, are not harmful.

Frequently Asked Questions

1. How can we detect alpha particles detected?

The following methods can be used to detect charged particles:

• Ionization chamber
• Scintillation counter
• Semiconductor detector

2. How do alpha particles interact with matter?

Alpha particles can interact with matter via coulombic forces. Due to their high ionization power, they can also lose energy by knocking an electron out of the atom they collide with.

3. Discuss the ionization and penetration power of alpha, beta, and gamma rays.

Alpha particles have a high ionization power, which is  times greater than beta rays and  times greater than gamma rays. However, their relatively higher mass lends them a low penetrating power, which is 1/1000 of beta rays and 1/100000 of gamma rays. But these particles can ionize biomolecules.

4. Is there a difference between alpha decay and alpha particle?

Yes. Alpha decay is the process by which, an unstable nucleus emits an alpha particle and a daughter nucleus. Alpha particles are the particles emitted in this process and are equivalent to doubly positively charged Helium atom.

5. Are alpha particles dangerous? How can we protect ourselves?

Alpha particles have high ionisation power, but their penetration depth is relatively low, which means they cannot penetrate the outer layer of our skin and thus, aren’t that harmful. 

However, if you inhale or ingest an alpha source, it can affect your organs internally, which may prove dangerous. The alpha radiation can reach your lungs, which may cause cancer. When consumed through water, it can affect the kidneys. Further, high levels of exposure to alpha radiation can lead to DNA damage, and even larger exposure can cause Acute Radiation Syndrome.

Protection from alpha radiation

Protection from alpha radiation is simple and may be achieved as follows:

1. Either decrease time of exposure or,
2. Move away from radiation source or,
3. Use a shield. 

Introduction

It is possible for elements in nature to change into another by various processes. Such processes are classified as nuclear reactions. For instance, nuclear decay is a type of reaction which occurs when an unstable nucleus emits energy, nucleons, and/or atoms to achieve stability. Various other types of reactions also exist.  

Various types of nuclear decay can occur in nature and one of those is alpha decay. This process occurs when a nucleus emits an alpha particle to gain stability. It might be worth mentioning that an alpha particle is very much like a Helium atom with a charge of +2e, i.e., two protons and two neutrons.  

Alpha Decay

Since alpha decay involves the emission of nucleons, parent nucleus, which is the nucleus undergoing alpha decay, is changed. Its atomic and mass numbers decrease by 2 and 4, respectively. Simultaneously, energy is also released in the form of electromagnetic radiation, which is why the process is termed radioactive. 

Alpha Decay Equation 

It is possible to represent nuclear reactions via equations. The general equation of alpha decay is as follows: 

Here, 

• X is the parent nucleus which undergoes alpha decay. 
• Y is the daughter nucleus which the parent is converted into. 
• α is the alpha particle that is emitted as a byproduct, along with energy. 

Understanding Q Value of Alpha Decay 

To understand the energy involved in a nuclear reaction and whether it is possible for the reaction to take place, Q value can be used. It is the difference in kinetic energies of initial and final nuclei and for alpha decay, we find it as follows: take the difference in the masses of the initial elements and the final products of the reaction, and multiply by \({c^2}\). That is, 

Here: 

• Q is the Q value of the reaction. 
• mi is the mass of the initial nucleus. 
• \({m_f}\) is the mass of the final nucleus. 

• \({m_α}\)  is alpha particle mass. 
• c represents the vacuum velocity of light. 

It should be noted that units are important while working with such equations. The above equation is for the case where masses are given in units of MeV/\({c^2}\). 

As previously mentioned, Q value can help us understand whether a reaction is possible. Not all elements can undergo all types of reactions. For example, whether alpha decay is possible depends on the Q value described above. Alpha decay is accompanied by a release of energy, which happens when the Q value is negative. 

On the other hand, a very stable parent nucleus will have greater mass than that of the final products, making the Q value positive. This would correspond to energy input instead of output, making alpha decay in such a case, unfavourable. Thus, Q value can help us understand whether a reaction is possible or not.

What are the Major Components of the Equation that Represents Alpha Decay? 

The alpha decay equation is as follows: 

Its major components are summarized below: 

• X represents the original or parent nucleus. Usually, this is an unstable element and it is observed that most elements undergoing alpha decay have mass numbers greater than 200. 
• Y is the nucleus obtained after the reaction is complete. It has lower mass and atomic numbers than the parent and as represented, these numbers decrease by 4 and 2, respectively. It is generally more stable. 
• α is the alpha particle. In simple words, alpha particles are just nuclei of Helium atom. 

Alpha Decay Example 

1. Decay of Radium-226 

The decay of Radium-226 is a common example. Ra-226 is a very stable isotope with half-life of 1600 years but it can undergo alpha decay to generate Radon gas. The process also releases ionizing radiation. 

The equation representing this decay is as follows: 

2. Decay of Uranium-238 

The decay of Uranium 238 into Thorium is one of the most commonly cited alpha decay examples. Take a look: 

What happens in Alpha Decay? 

We mentioned that the process of alpha decay is radioactive. That is, energy in the form of radiation is released. Further, alpha decay causes an unstable nucleus to change into a more stable one. This parent nucleus is generally heavy and when alpha decay occurs, it releases an alpha particle, which reduces its mass and makes it more stable. The alpha particle is ejected and travels a certain distance before becoming inert. 

Helium nucleus emission

Gamow Theory of Alpha Decay 

The energy of the alpha particle emitted can help us better understand the reaction. There are a large number of ways to measure this energy and a theoretical approach is to use Gamow’s theory, which connects the half-life of the process with the energy of the alpha particle. The foundation of this theory is in quantum mechanics and thus, its derivation is slightly complex. 

The theory assumes the daughter nucleus and the alpha particle to be present inside the parent before the reaction occurs. Since nuclear potential is immensely strong, classical mechanics forbids these nuclei from escaping. However, quantum mechanically, the concept of “tunnelling” allows for a small probability of escape for these particles. 

The relation derived from this hypothesis is the same as the one empirically derived by Geiger and Nuttal. It is summarized below: 

• λ is the decay constant. 
• Z is the atomic number of the parent. 
• E is the total kinetic energy of the daughter and the alpha particle. 
• \({a_1}\) and \({a_2}\) are constants.  

Summary

It is possible for certain elements in nature to be transformed into other elements via processes known as nuclear reactions. One common example of such reactions is nuclear decay, where an unstable nucleus decays into a more stable one by releasing energy and nucleons. Alpha decay is also a type of nuclear/radioactive decay, which occurs when an unstbale parent nucleus decays into a stabler one. In this process, an alpha particle is released, which is a Helium atom carrying a charge of +2e. The equation of alpha decay is given below:

In alpha decay, mass and atomic numbers reduce by 4 and 2, respectively.

Gamow’s theory of alpha decay relates half-life of parent with the energy of alpha particle and uses quantum mechanical calculations to arrive at the result. It posits that the products of the reaction are present in the parent already and the decay occurs by quantum mechanical tunnelling.

 

Frequently Asked Questions

1. Are alpha particles dangerous?

Alpha particles can not penetrate the human skin too much and thus, are comparatively safe. But since our eyes are sensitive, alpha particles can damage the cornea. Further, if an alpha particle source enters the body, it can damage organs from inside.

2. How far do alpha particles penetrate into matter?

Alpha particles easily absorbed even by a thin sheet of paper and they become inert after a few cm of travelling in air.

3. What is the typical kinetic energy of an alpha particle?

Alpha particles travel are heavy and thus, travel at around 5 MeV. This is equivalent to a velocity of 15,000 km/s.

4. What other types of nuclear decay are observed?

Alpha, beta, and gamma decay are three common nuclear decays of which, gamma decay is the most dangerous one. It emits high energy photons that can penetrate human skin and cause cancer.

5. What are the uses of alpha decay processes?

Americium-241 is an alpha particle source that is used in smoke detectors. The process is also used in artificial pacemakers for generating power. Other medical applications include Radium-223 for the treatment of bone cancer. 

Introduction

All of our energy is generated by fundamental chemical and physical processes. Throughout history, this has typically been accomplished by burning carbon-based resources such as wood, coal, and gas, or by utilising the energy of the sun, wind, and water. Through two physical processes known as fusion and fission, atoms can generate vast amounts of energy. They generate millions of times more energy than traditional sources through nuclear processes.

The history of nuclear fusion began at the turn of the 20th century with research into how stars generated their own energy. As potential applications increased to include warfare, energy generation, and rocket propulsion, the field’s emphasis broadened to include a comprehensive examination into the nature of matter and energy. In the 1930s, scientists, led by Hans Bethe, determined that nuclear fusion was the sun’s energy source and that it was both theoretically and practically practicable.

The term “fission” is used to describe the splitting of a heavy nucleus into two roughly equal-sized lighter nuclei. The revelation that such an unusual nuclear reaction could occur marked the conclusion of a really spectacular event in the history of science, and it ushered in an era of intense and fruitful research.

What is Nuclear Fission?

Fission refers to the fragmentation of anything into smaller pieces. In this sense, nuclear fission refers to the splitting or fragmentation of a large atom into two or more smaller atoms. These little atoms are technically light in weight. Breakdown of the nuclear fission process releases large amounts of energy, proving that it is an exothermic process. The uranium fission process is described below.

Nuclear Fission Reaction

What is Nuclear Fusion?

The word “fuse” means joining two or more other objects. The process by which two or more atoms come together to form a bigger atom is known as nuclear fusion. Because the act of fusing two atoms needs consuming energy, nuclear fusion is endothermic. 

The Distinction between Nuclear Fission and Nuclear Fusion in Tabular form:

Nuclear Fission vs Nuclear Fusion

What are Nuclear Fission and Nuclear Fusion in Physics?

The two basic natural forces that bind atoms together are weak and strong nuclear bonds. The total amount of energy held in atomic bonds is referred to as the binding energy. The greater the amount of binding energy stored inside the bonds, the more stable the atom. Atoms make additional efforts to promote stability by increasing their binding energy.

Nuclear Fusion versus Nuclear Fission

The differences between nuclear fusion and nuclear fission are given below :

Use of Nuclear Fission and Nuclear Fusion

 Both nuclear fission and fusion have many potential uses. Use of nuclear fission in power generation is significant.

•  Thermal energy for nuclear power plants is generated through nuclear fission. This heat is then used to turn water into steam, which is then used to power electrical generators. 
• About 21.5% of the electricity in the US comes from nuclear power plants. Nuclear fission employing uranium-235, which is also used in photographic sources, produces cesium-137 (Cs-137) and other rare radioisotopes. Nuclear fission energy can be used to power submarines and even some types of surface watercraft. Radioactive isotopes created from nuclear fission are employed in many types of medical imaging and cancer treatment.
• This is a perfect example of how nuclear fusion can be put to good use. After combining at the sun’s core, hydrogen nuclei release a tremendous amount of heat, which we feel as helium’s presence on Earth. Fusion might potentially become the primary commercial electricity generation method. 
• There are several potential applications for the energy produced by fusion reactions, including but not limited to: space heating, industrial processes, fissile fuel for fission reactors, and synthetic fuel.

Summary

An atom is split into two parts by a process known as nuclear fission, which is done to produce energy. The splitting of the uranium-235 nucleus when it is bombarded with neutrons is an important example of nuclear fission. On the other hand, it happens when two atoms combine and release energy. The name for this energy-producing process is nuclear fusion. This is how the Sun and other stars emit energy.

 

Frequently Asked Questions:

1. Apart from uranium, which other element is commonly used as fuel in fission reactors?

Ans: Thorium outnumbers uranium in the natural world. It can only be used as a fuel when combined with a fissile substance, like reprocessed plutonium, because it is fertile rather than fissile on its own. Fissile uranium-233 can be produced using thorium fuels and employed in a variety of nuclear reactor designs.

2. What is the moderator used in nuclear reactor?

Ans: To mitigate the dangers of fast-moving neutrons, a moderator is inserted into the nuclear reactor core. Forcing a nuclear chain reaction is much simplified by the inclusion of a moderator.

3. What particle is used to trigger the fission of a uranium nucleus?

Ans: Fission happens when a neutron collides with an atom, causing it to become excited and divide into two smaller atoms (called fission products). Moreover, extra neutrons are released, which can set off a chain reaction. Each atomic fission results in the release of vast amounts of energy.

Introduction

By treating an aryl hydrazone of a ketone/aldehyde with an acid or a variety of metal & dehydrated metal salt catalysts, \(N{H_3}\) may be removed, leading to the creation of an indole. This process is known as the Fischer indole synthesis. By directly putting an equal molar combination of aryl hydrazine as well as aldehyde/ketone into indolization settings, the actual separation of the aryl hydrazone is frequently avoided. Like this, the reduction of the appropriate aryldiazonium salt/ N-nitroso arylalkylamine in the vicinity of the CO compound results in the in-situ formation of the aryl hydrazine, which then immediately results in the aryl hydrazone. By treating pyruvic acid 1-methyl phenylhydrazone by HCl in 1883, Fischer & Jourdan achieved the very 1st indolization of an aryl hydrazone.

What is meant by Fischer Indole Synthesis?

It is one of the most effective and time-tested techniques for creating indoles. Fischer obtained the very 1st patent for it in 1883. In the introduction of acids, aryl hydrazine, as well as substituted ketone/aldehyde, can be used to create a variety of indoles. Under acidic circumstances, a phenylhydrazine, as well as a ketone/aldehyde, undergoes a chemical reaction to produce the heterocyclic aromatic indole.

The obvious benefit of this method is the usage of a wide variety of alcohols as opposed to their oxidized equivalents. The process may be completed in a single pot and offers moderate to good yields for the indoles while tolerating replacement on both hydrazines as well as alcohol. The parameters of idolization are frequently used without first isolating the aryl hydrazine using an equimolar combination of ketone/aldehyde. The same is true for aryl hydrazone, which may be immediately exposed to indolization settings in the vicinity of carbonyl without first isolating the aryl hydrazone. This is done by reducing the linked aryl diazonium /N-nitroso arylalkylamine salt.

The Fischer Indole Synthesis’s Main Features include:

1. Since the aryl hydrazones don’t have to be separated, the indole synthesis may be done in a single pot.
2. Unsymmetrical ketones generate 2 region-isomeric 2,3-disubstituted indoles exhibiting region-selectivity based on intermediate acidity, the substitution of hydrazine, as well as steric effects.
3. 1,2-diketones can be used to produce mono- as well as bis-indoles, having mono-indoles often being formed in refluxing alcohols with powerful acid catalysts.

Fischer Indole Synthesis Mechanism

Steps:

1. The product of aryl hydrazine and ketone is aryl hydrazone.
2. Protonation occurs at more basic N.
3. The proton is lost creating a pi bond neutralizing N to yield ene- hydrazone.
4. Again, protonation at the same N and undergo [3-3] sigmatropic shift generating a C-C bond at the ortho position of the benzene ring.
5. Isomerization takes place making a more stable aniline form and restoring the aromaticity of the ring.
6. N from aniline moiety attacks iminium ions intramolecular fashion to secure 5 membered rings.
7. One proton is lost, and acid catalyzes and by elimination of \(N{H_3}\), the final product, indole is formed.

Fischer Indolization

Fischer Indole Reaction is a convergent method that has been established to have an indole ring system that exists in many bioactive compounds. The method uses an irregular Fischer indolization sequence to condense hydrazines containing latent aldehydes. This eventually produces goods that include Indoline. The approach is convergent, gentle, simple to apply, all-encompassing, and may be applied to obtain enantioenriched products.

There has been the 1st catalytic Fischer asymmetric Indolization. When a spirocyclic chiral \({H_3}P{O_4}\) is present at a loading of 5 mol percent, it is highly enantioselective. Effective catalyst turnover has been accomplished by including a mildly acidic cation exchange resin that eliminates the ammonia produced. Different genera of three -substituted tetrahydro carbazoles are produced by the reaction, which may be carried out under favourable circumstances.

The discontinuous Fischer indolization is a powerful method for generating fused indole ring structures, which are present in several natural alkaloids. A brief description of the whole synthesis of communes is provided in alkaloids as well as perophoramidine. The method is focused on the usage of the disrupted Fischer indolization to produce the tetracyclic indole in natural products.

Fischer Indole Synthesis Procedure

Aryl hydrazine reacts with a ketone/aldehyde to produce an aryl hydrazone that isomerizes to the appropriate enzyme. A cyclic [3,3]-sigmatropic rearrangement results in the production of an imine following protonation. Under acid catalysis, the resultant imine forms a cyclic amino acetal, which removes \(N{H_3}\) to produce indole. Indole is a heterocyclic compound that is very important to biological systems. The redox-active indole side chain of tryptophan is one of the primary charge carriers engaged in the transfer of electrons in proteins. Tryptophan is one of the most important intrinsic fluorophores in the investigation of protein fluorescence due to the indole’s optical characteristics. Reductive deamination of tryptophan results in the intermediary molecule indole pyruvic acid, which is then converted into indole. The end products of the process are pyruvate, indole, ammonium, as well as water.

Summary

It can be concluded that under acidic circumstances, a phenylhydrazine, as well as a ketone/aldehyde, undergoes a reaction known as Fischer Indole Synthesis that results in the heterocyclic aromatic indole. Emil Fischer discovered the reaction in 1883. Today, this process is frequently used to create triptan-class antimigraine medications. Aryl hydrazine reacts with a ketone/aldehyde to produce an aryl hydrazone that isomerizes to the appropriate enzyme. A cyclic [3,3]-sigmatropic rearrangement results in the production of an imine following protonation. Under acid catalysis, the resultant imine forms a cyclic amino acetal, which removes \(N{H_3}\) to produce the energetically advantageous aromatic compound indole.

 

Frequently Asked Questions

1. Is indole basic or acidic?

Ans. Indole is a weak base, just like pyrrole. It interacts with KOH and Grignard reagents as well as polymerization by strong acids.

2. What is the Indole test?

Ans. Indole Test: This test shows that certain bacteria can break down the medium-accumulating amino acid tryptophan into indole. The test for indole synthesis is crucial for identifying Enterobacteriaceae.

3. What causes the electrophilic substitution reaction in indole?

Ans. The 3rd carbon in the indole ring is the most reactive site. This is even more reactive than benzene in terms of the electrophilic substitution process.

4. The indole ring is present in which amino acid?

Ans. L-tryptophan is the only protein amino acid (AA) with an indole ring, and when it undergoes biotransformation in living things, it either helps to preserve this chemical group in cells as well as tissues or breaks it down by producing a range of bioactive chemicals in both circumstances.

5. What reagent is utilized in the indole test?

Ans. Directly into the tube, add 5 drops of the Kovács reagent to check for the formation of indole. In a short time of introducing the reagent to the media, the reagent layer on top of the medium develops a pink to cherry-red ring, which signifies a positive indole test.

Introduction

A chemical is produced when primary alcohol is reacting with a carboxylic acid in the presence of sulphuric acid. The odour of this chemical is fruity and pleasant. The resulting chemical is known as ester. The chemical reaction that results in the creation of the ester is called an esterification reaction. There are three distinct pathways that lead to esterification,  by reacting acid anhydride with alcohol, by Chloroform and Alcohol or by acetic acid and ethanol. 

What is Meant by the Fischer Esterification Mechanism?

Producing an ester from a carboxylic acid and an alcohol in the presence of a strong acid catalyst is known as the Fischer Esterification Mechanism. Fischer esterification, named for its co-inventors Arthur Speir and Emil Fischer, is also commonly referred to as Fischer-Speier esterification. Alcohol and heat are required for the reaction to take occur. In 1895, they first described the Fischer Esterification process. In most cases, Fischer esterification can be reversed. Common catalysts for the Fischer Esterification Mechanism include sulphuric acid, p-toluene sulfonic acid (PTSA), and Lewis acids like  \({C_3}{F_9}{O_9}{S_3}Sc\) (Scandium triflate). The most stable ester appears to become the predominate product due to its latency, suggesting that this is essentially a thermodynamically regulated mechanism. This may be an essential feature when there are multiple reaction hotspots and unwanted byproduct esters to avoid. On the other hand, kinetic controls are commonly employed in reactions involving acid anhydrides and acid chlorides, which proceed quickly.

The Mechanism of Fischer Esterification

In the existence of abundant alcohol as well as a strong acid catalyst, this process transforms carboxylic acids to such an ester as the end product, including water as a residue. There are several stages in the mechanism-

1. The acid catalyst acts as a nucleophile of the carbonyl oxygen, allowing it to undergo a nucleophilic assault from ethanol initially.
2. The alcohol initiates a nucleophilic attack on the carbonyl. A solitary pair of electrons from the O atom of its alcohol bonds with carbonyl carbon, destroying its π bond with another O atom. The electrons in the bond go upwards to the O, neutralizing their positive electrical charge. It then generates an oxonium ion.
3. Following that, a proton exchange from the oxonium ion to the OH group occurs, culminating in quite an active site. It might be divided into 2 stages: firstly, the alcohol deprotonates that oxonium ion, producing the ternary complex, as well as subsequently the OH group adopts the alcohol’s proton.
4. Just after 1,2 removal of water, the protonated ester has been produced. A solitary O atom builds a π bond involving the carbon, liberating the water.
5. The leftover positively charged O has been deprotonated to produce the necessary ester.

Esterification Mechanism

Advantages of the Fischer Esterification Mechanism

Fischer esterification’s simplicity is one of its primary advantages over more traditional esterification processes. A simple acidic environment can be employed if acid-sensitive functional groups are never a worry; acidic medium could be used; softer acids should be included at the expense of prolonged reaction times.

However, the “direct” nature of the chemicals means that they have had a surprisingly small worldwide impact in terms of garbage and reagent toxicity.

Greenhouse gases or ozone depleters are two of the many environmental hazards that alkyl halides could pose.

The reaction of acid chlorides with atmospheric moisture produces hydrochloric acid gas and they appear to be extremely toxic, but they also react rapidly with water and other nucleophiles; they have been freely quenched from other nucleophiles apart from the preferred alcohol; and even its most popular formulation paths take into account the release of hazardous CO or \(S{O_2}\) gases.

Disadvantages of the Fischer Esterification Mechanism

Fisher esterification techniques have the limitations of being thermodynamically reversible and typically having sluggish reaction rates, which can range from many weeks to years depending on the reaction conditions. When other functional groups appear to be reactive to strong acid, alternatives may be problematic, and new catalytic acids may be selected.

If the generated ester has a lower boiling point than water and the reagents, it can be evaporated in its place. This is a common occurrence, as esters with no protic functional groups have a lower boiling point than their protic parental reactants. The reaction rate is slowed due to the restriction of the overall reaction temperature, but purification and extraction are simplified if the ester product can be purified independently from the reagents. Then, an excess of the starting material is typically required, and the reaction mixture is sealed before being gently heated.

Examples of the Fischer Esterification Mechanism

Summary

Indeed, Fischer esterification is a chemical process that changes carboxylic acid into an ester. There is a high concentration of alcohol and an active acid catalyst. Through the course of the reaction, there appears to be an even distribution of products and reactants. The formation of an acyl-enzyme intermediate is the initial step in the Fischer Esterification Mechanism. The ester bond is formed when the alcohol reacts with this intermediate. Ultimately, the ester product is hydrolyzed, releasing the enzyme. An ester has been formed within the presence of water, and this reversible process can only be prevented by continuously eliminating the ester. Fischer esterification’s inability to maintain equilibrium has been one of its drawbacks up to now. However, sulphuric acid is perhaps the most common and efficient acid catalyst throughout the esterification procedure. There should be equal proportions of carboxylic acid and sulfuric acid.

Frequently Asked Questions:

1. What is the role of the deprotonation in Fischer Esterification? 

Ans: The deprotonation of the alkoxide ion is necessary for the formation of the ester. It makes the nucleophile strong and favours the reaction kinetically. 

2. What drying agent is used in esterification?

Ans:. Concentrated sulphuric acid is the common dehydrating agent used for preparing esters. A carboxylic acid reacts with an alcohol in the presence of conc. sulphuric acid to form an ester. This process is known as esterification.

3. Why is HCl not used in esterification?

Esterifications are not water sensitive, because water is the reaction product. However, for this same reason, the concentration of the water in the reaction mixture affects the equilibrium point. Thus, it is completely unreasonable to use hydrochloric acid as a catalyst for preparative reactions.

Introduction

The rate of reactions is a word used to describe the rate at which a reaction occurs. The concentration of the reactants is a reliable indicator of the reaction rate. One can think of the rate of a reaction as being directly proportional to the production of the product and inversely proportional to the decreasing concentration of the reactant. The pace of reactions can be calculated with relative ease by tracking the shift in concentration.

For example, the combustion reaction on cellulose occurs rapidly, typically in a matter of seconds, and the rusting of iron is a relatively sluggish process that requires a long time to develop.

What is the Order of Reaction?

The Order of Reaction describes the correlation between process rate and species concentration in a chemical reaction. First, the rate expression (or rate equation) of the reaction must be determined in order to determine its order.

So, the order of a reaction is the exponents to which the reactant species are raised and it depends on the rate of that particular reaction. The order is achieved from the rate law. For example, in a reaction,

aA+bB⟶P

The rate equation is given as:

\(rate = k{[A]^x}{[B]^y}\)

The order of the reactant A is x fand for the reactant B, the order from the equation is y, Thus the overall order of the reaction,, n=x+y . 

Characteristics

• The sequencing of a reaction has certain defining features. There is no guarantee that the response order will always be a whole number. It is clear from the equations themselves that the amount of a reactant used to make a product is crucial. However, this feature is not always present. As a result, the amount of reactant present in a reaction is irrelevant to the outcome of the reaction in some cases. The order of reactions has so certain defining features depending on this. In the case of a zero-order reaction, in which the rate of a reaction is independent of the concentrations of the chemical species involved in the reaction, the order of the reaction is zero.
• Important information to keep in mind is that the reactant concentration may slow down the reaction as well. That is, the concentration of the reactant has a negative relationship to the reaction rate. The order would therefore take on a negative value in that scenario.
• Furthermore, the order of reaction can take a positive value, with the rate being proportional to the concentration. When the amount of a reactant rises, the pace of the reaction quickens.
• In addition, the rate of a reaction is not always a positive or negative integer; in some circumstances, it may be a non-integer value. Quite a few complex reactions involve situations where the values involved are not integers. 

How to Find Order of Reaction?

For every chemical reaction, the idea of the rate of reaction is very important. The order of reaction deals with the idea that how a reactant will influence the rate of a particular reaction. And by the knowledge of the order of reaction, we can focus more on the reactant that will be going to affect the rate of the chemical reaction. So, it is will not be obtained by simply looking into the chemical equation. It requires another method for finding the order of the reaction.

Following Methods Can be Used for Determination of Order of Reaction –

The order of reactions can be easily obtained by the following methods. 

• From the rate equation: By using the rate equation of chemical reactions we can find out the order of the reaction. For example, the order of the following rate is, \(Rate = K{[A]^2}\) , and the order is two.
• By doubling reactants: Doubling the concentration of reactants present chemical equations and observing its effect can help to find out the order of reactions. The experimental method is always used for the determination of order.
• Differential method: The method is also called the initial rate method. As it involves the determination of the rate of reaction by altering one of the reactant concentrations while the rest of the reactant is kept constant. 
• Graphical method: In this method, the chemical reaction that involves only one reactant is determined method. If A is the reactant involved, a graph is plotted in which logA vs time provides a straight line, it will be a first-order reaction. While the graph 1/A vs time is a straight line it will be second order.
• Integral method: The use of an integral form of rate law is used the determination the order of the reaction. 

Difference Between Molecularity and Order of Reaction 

Molecularity and order of reaction are two important terms that deal with chemical reactions. The difference between these two is tabulated below.

Zero Order Reaction 

Zeroth order or Zero-order reactions are chemical reactions that don’t rely on the concentration of chemical species involved in the reaction. The exponents of the reactant in the rate equation are zero.

\(Rate = K{[reactant]^0} = K\)

An example of a reaction that involves a zero-order reaction is the decomposition of N2OThe reaction is,

First Order Reaction 

The rate of reaction which counts on only one of the reactants is a first-order reaction. For such a reaction if the concentration of reactant is doubled the rate of the reaction will also get doubled. 

The rate equation for such reaction is,

rate=k[A]

Hydrolysis of cisplatin, the drug used for the treatment of cancer is an example of a first-order reaction.

Second Order Reaction 

The reaction in which the rate relies on the square of the concentration of reactant is a second-order reaction. For reactions,

2 A → products

The rate equation for the reaction will be,

\(Rate = K{[A]^2}\)

An example of such a reaction is the decomposition of Nitrogen dioxide,

\(2{\rm{ }}N{O_2} \to {\rm{ }}2{\rm{ }}NO{\rm{ }} + {O_2}\)

Pseudo First Order Reaction 

Even though they occur at the second order, their behaviour is more like to that of the first. Such chemical reactions have a pace that is proportional to the product of two reactants, but the appearance of the third reactant cannot be predicted because its concentration will fluctuate so wildly. As a pseudo-first-order reaction, the hydrolysis of ethyl acetate provides a good illustration.

Summary

There is a correlation between the rates of chemical reactions and their respective orders of reaction. Understanding rates is crucial for the development of chemical processes. When calculating the order of a chemical reaction, the exponents included in the concentration data are added together. The reaction order has a unique property in that it can take on negative, non-integer, and positive values.

Reactions are categorised as zero order, first order, second order, pseudo-order, etc., depending on the sequence in which they occur. There are a number of strategies that can be used to establish the reaction’s order. Similarity order of reaction also includes the concept of molecularity, which is commonly used to describe chemical processes. However, these two concepts are not the same at all.

Frequently Asked Questions

1. How does temperature affect the rate of a chemical reaction?

Ans: The reaction rates increase with temperature. Arrhenius Equation is an empirical connection that models the fluctuation of the rate constant with temperature, revealing chemical reaction rates at different temperatures.

2. How is half-life used in radioactive dating?

Ans: Scientists use specialized equipment to measure the amount of an unstable isotope in a sample and the amount of the isotope that it becomes after the isotope decays.

3. Does molecular size affect reaction rate?

Ans: The larger and more complex the reactant molecules, the less chance there is of a collision at the reactive site. Does larger the molecular size of the reactant, lower will be the rate of reaction. 

Introduction

The symbol for an element is a single letter or two-letter abbreviation of the element’s full name. These symbols are helpful when writing out lengthy chemical equations that need the usage of shortened forms of complexes and elements. The number of electrons (\({e^ – }\)) and protons (\({p^ – }\)) in an atom can be determined from its atomic number (Z). In chemistry, an element is defined as a pure substance made up entirely of atoms having the same number of protons in their atomic nuclei.

What are the First 20 Elements of the Periodic Table?

here is the list of 20 elements with symbols and Atomic Number 

Atomic number	Symbol	Element
20	Ca	Calcium
19	K	Potassium
18	Ar	Argon
17	Cl	Chlorine
16	S	Sulfur
15	P	Phosphorus
14	Si	Silicon
13	Al	Aluminum
12	Mg	Magnesium
11	Na	Sodium
10	Ne	Neon
9	F	Fluorine
8	O	Oxygen
7	N	Nitrogen
6	C	Carbon
5	B	Boron
4	Be	Beryllium
3	Li	Lithium
2	He	Helium
1	H	Hydrogen

Master the Periodic Table! Learn about all 118 elements, their symbols, and atomic numbers in our easy-to-understand article. Click here to start exploring now!

Importance of the Atomic Number of An Element in a Periodic Table

The number of protons in the nucleus or the number of electrons (\({e^ – }\)) in a neutral atom is equal to the atomic number. It determines the element’s position in the periodic table.

Eight is the atomic number of oxygen. This means that in the ground state of the nucleus, there are eight protons. There are eight electrons (\({e^ – }\)) in all. NaCl, with an atomic number of 11, also possesses 11 protons in its nucleus. There are 11 electrons in orbit around the nucleus.

 Since the number of electrons in an atom is also its atomic number, the electrical configuration of an atom may be easily predicted using just the atomic number. Because the atomic numbers in the contemporary periodic table increase, this is a very important fact. One final factor that is crucial in determining the properties of an element is its atomic number. The nature of chemical bonds is determined by the number of valence electrons (\({e^ – }\)). 

The periodic table’s atomic number is significant due to following reasons: 

1. If we order elements according to their atomic mass, we also need to list their isotopes, which makes the periodic table too long. However, if we arrange the periodic table according to the atomic number, we don’t need to write the isotopes.
2. If the periodic table were ordered by atomic mass, the element hydrogen (H), which has three isotopes, would occupy three separate spots.
3. The electrical configuration or valence electrons of an atom can be determined by its location in the periodic table, which is in turn determined by its atomic number.
4. The organisation of the elements according to their atomic numbers is simple to learn and copy.
5. If we know the atomic size based on the atomic number, we can use that information to make educated guesses about other properties of the element, such as its ionisation energy, electron affinity, and electronegativity. 
6. Atomic numbers allow us to determine an element’s oxidation state and valency by referencing its electronic configuration.
7. Metals (+ve charge elements) can be distinguished from nonmetals via their oxidation states (-ve charge elements).

How are the First 20 Elements of the Periodic Table Useful for us

The first 20 elements of the periodic table are important to us because they are the basis of all known forms of life. We can’t survive without these things in our bodies. Proteins, nucleic acid, and other building blocks are made from them. The first 20 elements of the periodic table are the most abundant elements on the planet. Some of the most important elements are:

1. Oxygen– It is required for respiration. The energy-producing mechanism that governs the metabolisms of most life forms is respiration. Humans, like many living beings, need oxygen to breathe.  It is produced during photosynthesis in plants as well as various microorganisms.
2. Carbon– It accounts for 18% of the body. It can be found in protein, sugar, & and other vital substances such as glucose. It can also be found in fossil fuels such as petroleum, CNG, & others.
3. Aluminium– Because it is malleable as well as soft, aluminium is utilised to select items such as utensils, aeroplane parts, window frames, & so on.
4. Silicon is a semiconductor that is utilised in computer chips.
5. Phosphorus– In the armed services, phosphorus is utilised to build weapons.  It is a crucial component of ATP, the body’s energy currency.
6. Calcium -It aids in bone strength maintenance. 

Noble Gases in the First 20 Elements of the Periodic Table

The noble gases are a set of six non-reactive gases found at the far right of the periodic table. They are located in the final group of the periodic table, Group 18. They lack aroma, colour, combustibility, and reactivity and have no discernible flavour. These subatomic particles can glow and carry an electric current. One organic chemist called these elements “lazy” because they don’t react with anything. Some examples of noble gases are radon, helium, xenon, krypton, neon, and argon. 

Summary

There are a total of 118 atoms in the periodic table. The first twenty elements of the periodic table is the first step towards mastering all of the elements. An element is a substance that can neither be oxidised nor reduced chemically. The elements’ atomic numbers follow the order in which they appear on the periodic table. We value the first 20 elements of the periodic table because they form the building blocks of all known life.

Without these in our systems, we just won’t make it. They are used as precursors in the synthesis of proteins, nucleic acid, and other biomolecules.

Frequently Asked Questions

1. What is the difference between a s-block element and a p-block element? 

Ans: S-block elements are elements in the s-block of the periodic table, while p-block elements are elements in the p-block of the periodic table.

2. Are all the first elements of the periodic table non metals?

Ans: No, all the first elements of the periodic table are not non metals. Hydrogen and the p block elements are non metals while the s block elements are metals. 

3. Are noble gases abundant in nature? 

Ans: Every one of the noble gases exists in the atmosphere. Argon makes up 0.934% of the air we breathe, whereas the other 18 elements are present in extremely minute quantities. The radioactive decay of (\({potassium^ 40 }\)) is the primary source of atmospheric argon. In the atmosphere, neon makes up 0.0018 percent, helium 0.00052%, krypton 0.00011%, and xenon 0.000009%.

4. What is the periodic table, and why is it important?

Ans: The periodic table is a chart that organizes chemical elements by their atomic number, electron configurations, and recurring chemical properties. It is important because it allows scientists to predict the properties of elements and their compounds, making it an essential tool in the study of chemistry and the development of new materials.

Introduction

The question of how aeroplanes stay up in the air has a very interesting answer. The physics behind it isn’t so complicated and can be easily understood if you understand what aerofoils are.

To understand aerofoils, one must first understand what forces aid in keeping aeroplanes up. There are four such forces known as drag, thrust, weight, and lift. The last one of these is what allows aeroplanes to take off into the air and thus, is the most interesting to understanding. 

Lift is generated when an object travels through air and “pushes” its surrounding molecules to make way for itself. This “pushing” action causes the object to experience aerodynamic force. Physically, this aerodynamic force may be resolved into two components, which are termed drag, and lift. These components act exactly as their name describes, i.e., the effect of lift is to “lift” up the object, while the effect of drag is to slow down its motion. From this basic introduction, it is easy to see that an object can only take off and fly when the lift is greater than the drag. Aerofoils make this balance possible. Let us discuss in detail.

What is Aerofoil? 

The word aerofoil does not refer to a single object. Instead, it refers to the cross-sections of special kinds of shapes which can generate the most favourable ratio between lift and drag forces. A few common types of aerofoils are shown in the image below and you can see how these shapes aren’t straight.

Aerofoil examples

The idea behind aerofoils is to maximize efficiency. It is not possible for any object to travel without experiencing drag force. However, aerofoils are designed so that they maximize lift while minimizing drag. What’s interesting, though, is the fact that aerofoils aren’t necessary for aeroplanes to fly. An aeroplane with flat plate wings can also theoretically take off, but the efficiency would be extremely low. This is what makes aerofoils so useful while designing aeroplanes.

Aerofoil Terminology

There are a few important terms, the understanding of which, is necessary for understanding the working of an aerofoil. The image below shows these terms and they are summarized below:

Aerofoil terminologies

1. Leading edge: Just as the name suggests, the leading edge is in the “lead”. That is, it collides with the air molecules first.
2. Trailing edge: This is the “tail” of the aerofoil and is the rear-most part.
3. Chord line: When we draw a straight line from the leading to the trailing edge, we get the chord line. Its length is known the chord and depending upon the shape of the aerofoil, it can even lie outside the aerofoil.
4. Angle of attack: When an aerofoil moves through the air, it “attacks” or “cuts” through air particles. The angle of attack is the angle made by the direction of the wind and the chord line. Take a look at the diagram for a better understanding.
5. Upper surface: While travelling through air, the upper portion of the aerofoil, experiences lower pressure and the air above it travels at a higher velocity. Thus surface is known as the upper or suction surface.
6. Lower surface: The pressure underneath the aerofoil is higher and thus, the bottom part of the aerofoil marks the lower or pressure surface.
7. Camber line: This line demarks the “center” of the aerofoil and divides it into upper and lower halves. The camber line may be curved depending on the aerofoil’s shapes and its distance from the chord line is a parameter known as the camber.

How does Aerofoil produce lift?

Air flow around aerofoil

The image above shows an aerofoil moving through air and the arrows represent the flow of air. You will notice that air particles tend to follow the same path as the shape of the aerofoil. When aerofoils have a curved shape, the air molecules follow that curved path as well.

When the angle of attack is properly adjusted, the curved flow of the air makes it so that upon collision with the aerofoil, a larger number of air molecules go underneath the aerofoil than above it. This naturally creates a pressure difference between the upper and lower surfaces of the aerofoil, which makes the air below it push it upwards. This pushing force is what we call lift. The curved shape of the aerofoil also minimizes the drag, allowing aerofoils to achieve take off very easily. 

Lift Coefficient

The lift coefficient relates the lift generated by the aerofoil to its area, as well as the velocity and density of the medium the aerofoil is travelling in. It is a dimensionless quantity which is larger when lift achieved is larger, and smaller otherwise.

The following equation sets up the lift coefficient.

Here:

We can derive lift coefficient from it and arrive at the following result.

Where q is the pressure of the fluid. The value of lift coefficient is derived experimentally and it summarizes exactly how the lift generated will depend on various factors.

Types of Aerofoils

We classify aerofoils into two categories based on geometry:

1. Symmetrical Aerofoil

A symmetrical aerofoil

When the upper and lower surfaces of the aerofoil are congruent, it is termed as a symmetrical aerofoil. In such aerofoils, the chord line and the camber line coincide and perfectly divide the aerofoil into equal halves. They are generally used in helicopter blades and produce no lift if the angle of attack is zero.

2. Non-symmetrical Aerofoil

A symmetrical aerofoil

As can be seen from the image above, non-symmetrical aerofoils have unequal upper and lower halves. The chord and camber lines are separated from each other and the latter is curved. While such aerofoils can even work with zero angle of attack, they aren’t very economical.

Summary

Lift, thrust, drag, and weight are important forces which come into play when aeroplanes fly. Lift and drag are connected to each other and in fact, are components of the aerodynamic force that an object experiences while moving through a gluid. Lift pushes the object up, and drag slows it down. Aerofoils refers to cross-sections of shapes that are designed to maximize lift and minimize drag. This happens because aerofoils push a larger amount of air beneath them, leading to a pressure difference. They are classified into symmetrical and non-symmetrical types depending on geometry, and non-symmetrical aerofoils are more efficient but less economical.

 

Frequently Asked Questions

1. Who designed and invented aerofoils?

Max Munk, a German mathematician, first envisioned aerofoils. Later, Hermann Glauert made improvements to their design in the 1920s.

2. Where are aerofoils used?

Aerofoils are used in the wings and rotors of all aircrafts and helicopters. Wind turbines also have an aerofoil shape and the aeronautics sector makes the most use of aerofoils.

3. What is the significance of the four forces that aid an aircraft to fly?

An aircraft’s weight pushes it downwards, while thrust moves it forward. Drag slows it down and lift pushes it upwards. All four forces must be considered when studying aircraft.

4. At what angle of attack is the maximum lift force generated?

The maximum lift force is generated at the critical or stall angle of attack. This angle varies based on various factors, but for most aerofoils, it is between 15-20 degrees.

5. Is the concept of aerofoils applicable in liquids too?

Yes. The principles remain similar when an object moves through a liquid, but in that case, the term hydrofoil is used instead of aerofoil.

Introduction

The accelerometer is a device used to measure the acceleration of an object. The sensors present in an accelerometer allow us to measure and analyse both linear as well as angular acceleration. This device has a wide range of applications in our day to day life and forms a vital component of numerous basic systems and devices. 

An accelerometer measures acceleration forces in terms of the “g” unit, and can perform measurements in one, two, or three planes. It can also trigger a response or alarm if a certain threshold is exceeded. There are three main types of accelerometers: capacitive, piezoelectric, and piezoresistive. Accelerometers are most commonly used in guidance systems and inertial navigation.

What is an Accelerometer?

An accelerometer is a device used to measure and analyse linear and angular acceleration. It is a crucial component for many systems and devices in various aspects of our lives. Acceleration forces can be categorised into two types: static and dynamic.  Static forces, such as friction and gravity, are forces that are continuously applied to an object. Dynamic forces, which are also known as moving forces, are forces that are applied at different rates. One common example could be the vibration of a string. 

In vehicles, accelerometers are used in collision safety systems and can detect rapid deceleration. When a dynamic force is detected, the accelerometer sends an electronic signal to an embedded computer, triggering the deployment of airbags.

How does an Accelerometer work?

• The accelerometer operates on a simple principle: it measures acceleration forces and takes readings in one, two, or three planes. 
• A routine can be triggered once a threshold is exceeded, allowing us to develop smart devices. 
• A 3-axis accelerometer is the most commonly used type of accelerometer. It consists of three separate accelerometers that measure acceleration in the X, Y, and Z planes. 
• The OKYSTAR OKY3230 is a common example of such an accelerometer which, when in a stable position with no external acceleration, will only measure the force of gravity. 
• If a 3-axis accelerometer is positioned such that the X axis points to the left, the Y axis downward, and the Z axis forward, it will provide the following readings.

X = 0g

Y = 1g

Z = 0g

Accelerometer chip

Types of accelerometers

An accelerometer is a device used for measuring the rate of change in an object’s velocity. It uses an electromagnetic sensor to monitor the object or determine its position in space. An accelerometer can measure both static and dynamic acceleration. 

The three main types of accelerometers are:

Capacitive accelerometer: The Capacitive Accelerometer operates on the principle of measuring the change in electrical capacitance to determine the acceleration of an object. Here are a few salient features:

• This is the most widely used accelerometer type, and is considered to be the least expensive and compact in comparison to the other types.
• It is a micro-electromechanical system, composed of components ranging from 1 to 100 micrometres. 
• The working of the accelerometer is based on the displacement of a known mass suspended on springs, where one end of the spring is attached to the mass and the other end is attached to the capacitor.
• Any force experienced by the sensor results in the movement of the mass, causing a change in the distance between the capacitor plates, thereby altering the capacitance. 
• However, it is to be noted that the accuracy of this accelerometer is lower for high amplitude signals and frequencies compared to the other types.

Accelerometer chip

Piezoelectric accelerometer: The Piezoelectric accelerometer measures acceleration by utilising the piezoelectric effect. A few important points to note about it are given below:

• This type of accelerometer is based on a principle that is similar to that of the piezoresistive one. The material, typically PZT, undergoes deformation when subjected to acceleration, causing a change in the electric charge.
• Piezoelectric accelerometers offer high sensitivity and accuracy, making them useful for advanced seismic estimation, crash and impact tests, and other applications that require accurate measurements. 
• They can be employed in a wide range of implementations due to their exceptional performance characteristics.

Piezoelectric accelerometer

Piezoresistance accelerometers: These accelerometers are based on the change in resistance of their components when undergoing acceleration.

• The sensitivity of these devices is dwarfed by that of piezoelectric ones.
• The piezoresistive effect is the change in electrical resistivity of a material when mechanical stress is applied. The accelerometer is able to convert this change in resistance into an electrical signal.
• While the measuring range is high for this type of accelerometers, and we can measure slow-changing signals, they must be kept at a steady temperature and cannot perform well with small signals or changes.

Purpose of accelerometer

An accelerometer in vehicles measures acceleration, which is produced by motion or gravity. Its main task is to convert mechanical motion into electrical signals.

Applications of accelerometer

An accelerometer is a device that can measure acceleration of a body. Its range of application is enormous and the most common example is in inertial navigation. Some other common uses are:

• Airbag deployment in automobiles uses accelerometers.
• It can measure seismic activity and inclination.
• The depth of CPR chest compressions may also be measured via accelerometers.
• Accelerometers are used as orientation sensors in smart devices, allowing for auto rotation.
• A large number of modern electronic devices utilise accelerometers.

Summary

An accelerometer is a device for measuring linear and angular acceleration by analysing force. It operates based on a simple principle and can take measurement in one, two, or three planes. Accelerometers can be classified into three main types: capacitive accelerometers, piezoelectric accelerometers, and piezoresistance accelerometers. The number of uses of accelerometers in science and industry are enormous and the most common use is for the aircraft or the missiles in the inertial navigation systems.

 

Frequently Asked Question

1. What is a gravimeter?

An accelerometer configured specifically for the measurement of gravity is known as a gravimeter.

2. What is the most common use of accelerometers?

Aircrafts, missiles, and navigation systems make the most use of accelerometers.

3. What are MEMS accelerometers?

These are accelerometers that can detect changes in the mico-scale. The acronym corresponds to micro-electro-mechanical systems and these accelerometers are used in a large number of devices.

4. How can an accelerometer be used for hard drive protection?

Ans: If a hard drive undergoes excessive stress or vibration, an accelerometer can detect it and protect the data by separating the reader head from the disc. This prevents scratches and data corruption.

5. What are the key characteristics we need to keep in mind while selecting an accelerometer?

Ans: The bandwidth of the sensor, its sensitivity, frequency response, and the dynamic range are the most important characteristics while choosing an accelerometer for a particular use-case.