What is electron affinity? | Chemistry | Extraclass.com

Watch More Videos @ http://bit.ly/extraclassapp, http://extraclass.com/

This video will help you to learn What is electron affinity?

What is electron affinity?

Electron affinity is the change in energy that occurs when a neutral atom in the gaseous phase gains an electron and releases energy in the process.

In simple terms, it is the likelihood of a neutral atom to gain an electron.

As we know that an electron carries a negative charge, so when a neutral atom gains an electron, it changes into a negative ion.

Since the release of energy is an exothermic process, therefore the change in energy has a negative sign which means that the electron affinity is positive.

On the basis of this sign convention, we must remember that higher electron affinity indicates the stronger capability of an atom to easily accept electrons.

Or we can say that an atom with a lower electron affinity will not accept electrons as easily.
There are two types of electron affinities, we must learn about

first electron affinity and second electron affinity

First Electron Affinity is the energy released when an electron is added to a neutral atom.
And second electron affinity is the energy released when an electron is added to a negative ion

the second electron affinity is positive because more energy is required to add an electron to a negative ion as compared to a neutral atom

For example, the first electron affinity of oxygen is minus 142-kilo joules per mole while second electron affinity is plus 844-kilo joules per mole

As we know that Ionization energies are always concerned with the formation of positive ions.

Electron affinities are the negative ion equivalent of ionization energy and their use is almost always confined to elements in groups 16 and 17 of the Periodic Table.

Factors Affecting Electron Affinity

Electron affinity of an element depends on
• The extent of nuclear charge
• Size of the atom
• Stability of valence shell electronic configuration

Effective Nuclear charge

Nuclear charge is also synonymous to the atomic number, which is equal to the number of protons present in the nucleus

Protons are positive subatomic particles. higher the number of protons in atoms, the greater is the attractive force applied on electrons and higher is the electron affinity Atomic size of Atomic Radius

When the size or radius of an atom increases, the electron entering the outermost orbit is more weakly attracted by the nucleus and the value of electron affinity is lower. That means the electron affinity is higher for smaller atoms.

Also, the Shielding effect is directly proportional to atomic size and atomic size is inversely
proportional to electron affinity.

Electronic Configuration

Adding electrons to atoms with stable electronic configuration is difficult than adding to atoms with unstable electronic configuration

The stability of the configuration having fully-filled orbitals (p6, d10, f14) and half-filled orbital (p3, d5, f7) is relatively higher than that of other configurations,

Thanks for watching

Download Extraclass.com app: - Play Store: http://bit.ly/extraclassapp

Follow us on our social media handles to stay updated.

Website – https://www.extraclass.com/
Facebook -   / extraclassofficial  
Instagram -   / extraclassofficial  
Youtube -    / extraclass  
Twitter -   / extraclass_com  
Happy Learning!!
“Thanks for watching”.
#Extraclass
#electronaffinity
#chemistry
#cbse
#neet
#jee