Electro Negativity

Question 1

Definition of “electronegativity”.

Answer 1

Electronegativity is the ability of an atom to attract the pair of electrons in a covalent bond.

Question 2

What three factors does electro negativity depend on?

Answer 2

1. Size of positive charge on the nucleus.
   •Moving from left to right across a period, the number of protons in the nucleus increases.
   •Increase in positive charge increases the attraction between the nucleus and the pair of electrons in the covalent bond.
   •So elements in the right of the periodic table are more electronegative than those on the left.
2. Atomic radius
   • The smaller the atomic radius, the closer the bonding electrons will be to the nucleus of an atom.
   • As we move from left to right across a period, atomic radius decreases.
   • Elements on the right of the periodic table are more electronegative than those on the left.
3. Shielding of the nucleus by electrons in the inner shells.
   • Electrons in the inner shell screen electrons in the outer shell from the positive charge of the nucleus.
   • The greater number of inner shells, the lower the electronegativity.