Question

Define electronegativity? How does it differ from electron gain enthalpy?

Answer 1

Electronegativity:

• The tendency of an atom in a molecule to attract the shared pair of electrons towards itself is known as electronegativity.
• There is no specific unit for electronegativity. In the modern periodic table:
• In the modern periodic table: as we move left to right, across a period the nuclear charge increases, atomic size decreases, and electronegativity value increases.
• As we move down the group there is an increase in the atomic number also nuclear charge and a decrease in the electronegativity value.
• In general, metal shows a lower electronegativity value compared to on-metals.

Electronegativity:	Electron gain enthalpy
1. An atom in a molecule tends to attract the shared pair of electrons towards itself known as electronegativity.	1. Electron gain enthalpy is defined as the amount of energy released when an electron is added to an isolated gaseous atom.
2. It is the property of a bonded atom.	2. It is the property of an isolated atom.
3. It has no unit.	3. Its unit is KJ/ mol.
4. The values of electronegativity cannot be determined experimentally.	4. An element has a constant value of the electron gain enthalpy that can be calculated experimentally.