Question

what is known as electron affinity

Answer 1

HEY MATE

UR ANSWER IS

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electron affinity

so we understand this thing by one example

let think  you're carrying a hand bag and adding things to it. Naturally, the  hand bag becomes heavier, and there is a change in the energy you expend when the weight changes. In the same way, when an atom gains electrons, an energy change occurs. This energy change is what we call the electron affinity.

we define electron affinity =the energy change that occurs when an atom gains an electron, releasing energy in the process.

[ note = an electron is negatively charged, so when an atom gains an electron, it becomes a negative ion. ]

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Factors That Affect Electron Affinity

there are some factors

-- Atomic size :-

--»Nuclear charge :-

--»Screening effect :-

--»Electronic configuration :-

1.  ATOMIC SIZE

we simple  understand this by Larger the size of an atom, larger will be the distance between the nucleus and the incoming electron.  the smallerone  will be force of attraction felt by incoming electron and hence smaller will be the value of Electron affinity .

2.  NUCLEAR CHARGE

we simple  understand this by Greater the nuclear charge, greater will be the attraction for the incoming electron and as a result larger will be the value of electron affinity.

3.  Screening effect

Screening effect is inversely proportional to electron affinity

4.  Electronic configuration

we know very well Stable the configuration of an atom, lesser will be its tendency to accept an electron and hence lower the value of its electron affinity

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Highest and lowest electron affinity

Highest E.A. : Chlorine. (-ve)

Lovest E.A.: Mercury. (-ve)

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electron affinity decrease across a period

Electron affinity decreases down the groups and from right to left across the periods on the periodic table because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.  one might think that since the number of valence electrons increase going down in the group, the element should be more stable and have higher electron affinity. One fails to account for the shielding affect. if/as one goes down the period, the shielding effect increases, thus repulsion occurs between the electrons. This all is happen  bcoz  of  the attraction between the electron and the nucleus decreases as one goes down the group in the periodic table.

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Thank uhh

Answer 2

Hello mate here is ur answer :-) :-)

Let's firstly understand what is affinity

Affinity :-

1. It is related to receiving fundamental particles.

2. According to chemistry , affinity is the force by which atoms are held together in chemical compounds.

Now, what is electron?

1. Electrons are negatively charged particles.

2. It is a part of atom (all the materials made up of tiny particles called atoms) .

3. its symbol is e- .

4. It can be either free (not attached to any atom), or bound to the nucleus of an atom.

Thus , Now we can easily understand what is electron affinity.

Electron affinity is simply the energy required to add an electron in an isolated gaseous form.

It is also called electron gain enthaply.

It is exothermic in nature .

The electron affinity of non metals is generally higher than metals.

Electron affinity can be defined by the following equation :-

A(g) + e- ----------> A-(g) + energy released.

Hope it helps you........!!!!

Thanks :-)