Tag: Electron Affinity

Introduction: 

An alteration in an atom’s energy is known as electron affinity. An atom gains a negative charge and releases energy as more electrons are added to its outer shell. In order to stabilise its octet, an element obtains electrons. When an element receives or loses an electron, energy is released. An exothermic reaction occurs when an element takes an electron to form a compound, releasing energy in the process. An exothermic process releases energy because a nucleus from another element is using it to attract the electron. An endothermic process is one in which energy is absorbed when an element loses an electron. An atom gets energy when one or more of its electrons are lost.

What is electron Affinity?

A molecule either loses or gains energy during a chemical reaction. Energy is gained or lost as electrons are gained or lost. Exothermic reactions occur when an atom loses an electron, releasing energy. Chemical reactions in which electrons are lost are called endothermic because they consume energy. The ability to accept an electron is referred to as the electron’s affinity. when a neutral gaseous atom accepts the electron, it will charge with a negative ion. There is always a negative value for the first electron affinity and a positive value for the second. Atomic electron affinity measurements are notoriously imprecise. Ionic compounds’ energy dissipation is used as a proxy for this. The propensity of an atom to act as an oxidising or reducing agent is another indicator of its electron affinity. Kilojoules per mole is the unit of measure. Ea represents the attraction between electrons.

First Electron Affinity: 

When an electron is added to an atom that is electrically neutral, the atom gains a negative charge and releases energy. Since greater energy is needed to draw an electron via the nucleus, the initial electron affinity is usually negative. 

The common trends followed in the periodic table are: 

• When one moves down the periodic table, electron affinity decreases.
• The electron affinity rises as we progress from left to right over the time.
• When metals lose an electron, they become cations.
• When a nonmetal accepts an electron, it forms an anion. 
• Due to the ease with which they may lose an electron from their outer shell, metals have a lower electron affinity than nonmetals.
• It is an endothermic process for metals to lose one electron because the outer shell electrons have less attraction. An Element of Matter

Electron Affinity of atom

Second Electron Affinity:

Gaining an electron is the anion’s second electron affinity. Second electron affinity manifests itself in the group-16 elements oxygen, sulphur, and selenium because these elements form anions with (-2) ions.

For example: 

The electron affinity of oxygen is given as;

The second electron affinity is higher than the first electron affinity in oxygen molecules because of the electron-electron repulsion in the negatively charged ion of oxygen. 

Factors Affecting Electron Affinity:

The electrical arrangement of atoms, the nuclear charge of the molecules, and the atomic size all play a role in determining a molecule’s electron affinity.

1. Atomic size and its effect: The electron affinity of smaller atoms is higher than that of larger ones. The nucleus of a smaller atom is more alluring to the electrons than the nucleus of a larger atom. Attraction for electrons in the outer shell will diminish as atom size grows because the outer shell will be further from the nucleus. For instance, Br has a lower electron affinity than I. 
2. The electron affinity is also affected by the nuclear charge. A higher atomic charge results in a stronger electron attraction, and hence a higher electron affinity. When a molecule is already charged, the repulsion between its electrons and the pull from the nucleus both increase, leading to a lower electron affinity in the charged ion.
3. Reducing the screening effect on the inner shell of an atom increases its electron affinity.
4. The electron affinity is also affected by the electrical configuration. Inert gases will have zero electron affinity because elements with a complete octet have no propensity to receive electrons. An important factor in electron affinity is the electrical configuration. Because of their unique electrical structure, metals have a lower electron affinity compared to non-metals.

Summary

The capacity to take electrons in a gaseous state and transform into an anion is known as electron affinity. The process of receiving electrons is exothermic because it results in the release of energy. The electron affinity reduces when we travel up to down in groups and rises while moving left to right in a period. It is denoted by the symbol Ea, and it is measured in kilojoule per mole (KJ/Mol). In all cases, the electron-electron repulsion causes the first electron affinity to be lower than the second electron affinity. The electronic configuration, screening effect, and nuclear charge of elements all have a role in how strongly they attract electrons.

Frequently Asked Questions

1. Why does fluorine have less electron affinity as compared to Chlorine?

As we move along a period, electron affinity increases and decreases down a group. However, the fluorine atom is too tiny to release a significant quantity of energy. Hence, among the halogens, chlorine has the highest electron affinity value, followed by fluorine, bromine, and iodine.

2. Group 1 or group 7—which is more reactive in the periodic table?

Group 7’s nonmetals, the halogens, become progressively less reactive as you move from top to bottom of the group. This pattern runs counter to what we observe in Group 1 of the periodic table, which contains the alkali metals.

 3. What is the sign of electron affinity?

Adding an electron to an element makes it less positive, hence the electron affinity is negative at initially. Nevertheless, adding an electron to a negative ion might make it more positive or more negative depending on the nature of the repulsion between the electrons.

Introduction

An atom’s energy changes due to electron affinity. A neutral atom gains energy and a negative charge when electrons are added to its outer shell. To stabilise its octet, an element gains electrons. When an element accepts or loses an electron, energy is released. When an element accepts an electron to form a compound, it releases energy, which is referred to as an exothermic reaction. The energy is released in an exothermic reaction in order to attract the electron by a nucleus from another element. When an element loses an electron, it absorbs energy, a process known as endothermic. An atom gains energy when it loses electrons.

What do you mean by Electron Affinity?

When atoms accept electrons, they emit energy, which is referred to as an exothermic reaction. Atoms that lose an electron in a chemical reaction, on the other hand, absorb energy and are known as endothermic reactions. The ability to accept an electron is referred to as electron affinity. When a neutral gaseous atom accepts an electron, it gains a negative ion charge. The first electron affinity is always negative, while the second is always positive. It is difficult to measure the electron affinity of an atom. It is determined by the energy released by ionic compounds. The electron affinity is also measured by an atom’s tendency to act as an oxidising or reducing agent. It is measured in kilojoules/moles. Electron affinity is symbolised by EA.

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Factors Influencing Electron Affinity

The atomic size of the element, the nuclear charge on the molecules, and the electronic configuration of atoms are all factors that influence a molecule’s electron affinity.

1. Atomic size: Atoms with smaller sizes have greater electron affinity than atoms with larger sizes. The nucleus of smaller atoms is more attractive to electrons than the nucleus of larger atoms. As the atom’s size increases, the outer shell becomes further away from the nucleus, and the attraction for electrons in the outer shell decreases. 
2. Nuclear Charge: The nuclear charge influences electron affinity as well. As the charge on an atom increases, so does the attraction in electrons, and thus the electron affinity. When a molecule is already charged, electron repulsion increases, and the pull from the nucleus increases, resulting in increased electron affinity in charged ions.
3. Shielding Effect: As the screening effect on an atom’s inner shell is reduced, the electron affinity increases.
4. Electronic Configuration: The electronic configuration also affects electron affinity. Because elements with full octets have zero tendencies to accept electrons, electron affinity in inert gases is zero. The electronic configuration is crucial in electron affinity. Metals have a lower affinity for electrons than non-metals due to their electronic configuration.

Summary

The ability to accept electrons in gaseous form and form an anion is referred to as electron affinity. The process of accepting electrons generates energy, which is why it is referred to as an exothermic process. When we move from group to group, the electron affinity decreases and increases when we move from period to period. It is denoted by the symbol EA and measured in Kilojoules per Mole (KJ/Mol). Because of electron-electron repulsion, the first electron affinity is always less than the second electron affinity. The atomic size, electronic configuration, screening effect, and nuclear charge of elements all influence electron affinity.

Frequently Asked Questions

1. Why do noble gases have no electron affinity?

Ans. Noble gases have zero electron affinity because their octet is complete, and they do not have an affinity for electrons. As a result, noble gases have no electron affinity.

2. Why does group 17 have such a strong electron affinity?

Ans. Because the halogens are small and have more electrons in the outer shell, the elements of the halogens group have a high electron affinity. A halogen would rather accept an electron than lose seven electrons to complete its octet.

3. Why does fluorine have a lower electron affinity than chlorine?

Ans. Because the atomic size of fluorine molecules is smaller than that of chlorine molecules, the outer shell of fluorine is already filled with electrons, and the nucleus is much closer to the outer shell, the electron repulsion is greater than the force of attraction of the nucleus when an electron is placed in the outer shell of fluorine molecules compared to chlorine molecules.

Introduction

Chemical elements are the fundamental building blocks of chemistry, and everything around us is made up of elements. The periodic table is a tabular display of elements found in chemistry that are arranged by atomic number. A periodic table is an important tool for chemists, material scientists, and nanotechnologists because it provides so much information about the elements that it is easy to predict the physical and chemical properties of the elements. The periodic table demonstrates a fundamental but critical principle that the atomic number is responsible for chemical properties.

The periodic table contains how many elements?

The periodic table contains 118 elements organized in 7 rows and 18 columns. The rows (from left to right) are called ‘periods,’ and the columns (from top to bottom) are called ‘groups.’ All chemical elements have different physical and chemical properties, which change as you move in the periodic table. The arrangement is made so that the elements in the same column have similar properties. Surprisingly, only 94 of these 118 elements exist naturally.

118 Elements Name and Symbols and Atomic Numbers in Chemistry

Name of the Element	Symbol	Atomic Number
Hydrogen	H	1
Helium	He	2
Lithium	Li	3
Beryllium	Be	4
Boron	B	5
Carbon	C	6
Nitrogen	N	7
Oxygen	O	8
Fluorine	F	9
Neon	Ne	10
Sodium	Na	11
Magnesium	Mg	12
Aluminium	Al	13
Silicon	Si	14
Phosphorus	P	15
Sulphur	S	16
Chlorine	Cl	17
Argon	Ar	18
Potassium	K	19
Calcium	Ca	20
Scandium	Sc	21
Titanium	Ti	22
Vanadium	V	23
Chromium	Cr	24
Manganese	Mn	25
Iron	Fe	26
Cobalt	Co	27
Nickel	Ni	28
Copper	Cu	29
Zinc	Zn	30
Gallium	Ga	31
Germanium	Ge	32
Arsenic	As	33
Selenium	Se	34
Bromine	Br	35
Krypton	Kr	36
Rubidium	Rb	37
Strontium	Sr	38
Yttrium	Y	39
Zirconium	Zr	40
Niobium	Nb	41
Molybdenum	Mo	42
Technetium	Tc	43
Ruthenium	Ru	44
Rhodium	Rh	45
Palladium	Pd	46
Silver	Ag	47
Cadmium	Cd	48
Indium	In	49
Tin	Sn	50
Antimony	Sb	51
Tellurium	Te	52
Iodine	I	53
Xenon	Xe	54
Cesium	Cs	55
Barium	Ba	56
Lanthanum	La	57
Cerium	Ce	58
Praseodymium	Pr	59
Neodymium	Nd	60
Promethium	Pm	61
Samarium	Sm	62
Europium	Eu	63
Gadolinium	Gd	64
Terbium	Tb	65
Dysprosium	Dy	66
Holmium	Ho	67
Erbium	Er	68
Thulium	Tm	69
Ytterbium	Yb	70
Lutetium	Lu	71
Hafnium	Hf	72
Tantalum	Ta	73
Tungsten	W	74
Rhenium	Re	75
Osmium	Os	76
Iridium	Ir	77
Platinum	Pt	78
Gold	Au	79
Mercury	Hg	80
Thallium	Tl	81
Lead	Pb	82
Bismuth	Bi	83
Polonium	Po	84
Astatine	At	85
Radon	Rn	86
Francium	Fr	87
Radium	Ra	88
Actinium	Ac	89
Thorium	Th	90
Protactinium	Pa	91
Uranium	U	92
Neptunium	Np	93
Plutonium	Pu	94
Americium	Am	95
Curium	Cm	96
Berkelium	Bk	97
Californium	Cf	98
Einsteinium	Es	99
Fermium	Fm	100
Mendelevium	Md	101
Nobelium	No	102
Lawrencium	Lr	103
Rutherfordium	Rf	104
Dubnium	Db	105
Seaborgium	Sg	106
Bohrium	Bh	107
Hassium	Hs	108
Meitnerium	Mt	109
Darmstadtium	Ds	110
Roentgenium	Rg	111
Copernicium	Cn	112
Nihonium	Nh	113
Flerovium	Fl	114
Moscovium	Mc	115
Livermorium	Lv	116
Tennessine	Ts	117
Oganesson	Og	118

The characteristics of the Periodic table

1. Electronegativity

2. Ionization Energy

3. Electron Affinity

4. Atomic Radius

Summary

To date, mankind has discovered 118 elements. Only 94 of these occur naturally. These elements are represented in the periodic table, which has seven rows and eighteen columns. Columns represent groups, and rows represent periods. All elements are members of similar groups with similar chemical properties. The chemical properties of elements are determined by their atomic number. The number of protons in the atom determines the atomic number. This number also indicates the number of electrons in the atom. The chemical properties of an element are determined by the electrons in the valence cells.

Frequently Asked Questions

1. Why do elements in the same group share physical and chemical properties?

Ans. The physical and chemical properties of elements depend on the number of valence electrons. Elements present in the same group have the same number of valence electrons. Therefore, elements present in the same group have similar physical and chemical properties.

2. Why are noble gases also called inert gases?

Ans. Noble gases are also known as inert gases because their electron configuration is the most stable. Because the valence shells are completely filled, they cannot lose or gain electrons.

3. Why ionization energy is always positive?

Ans. Electrons in an atom are bounded by forces of attraction from the nucleus. And we know the electron will be attracted to the nucleus due to the charge difference. This means the energy that is provided to take out an electron from its shell. This is why the ionization energy is always positive.