Electronegativity

Question 1

Define electronegativity

Answer 1

Electronegativity is the relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond

Question 2

What did the American chemist, Linus Pauling study?

Answer 2

He studied the amounts of energy needed to break certain bonds.
From his results he set up a scale of relative values of electronegativity.

Question 3

Summarise the important points about electronegativity (2)

Answer 3

1. Elements with low electronegativity values are said to be electropositive.
2. Since chlorine is more electronegative than hydrogen, they refer to the bond H-Cl as a polar covalent bond.
   Hydrogen chloride is a polar covalent molecule or simply a polar molecule.
3. The word ‘polar’ simply means (a) that the bonding electrons are not shared equally, (b) that there is a spatial positive and a partial negative charge on the molecule and (c) that these partial charges are separated by some distance.

Question 4

Define a polar covalent bond

Answer 4

It is a bond in which there is unequal sharing of the pair (or pairs) of electrons.
This causes one end of the bond to be slightly positive and the other end slightly negative.

Question 5

The term pure covalent is referred to as what?

Answer 5

The term pure covalent is often used to refer to a covalent bond where there is equal sharing of the two electrons in the bond (There is equal sharing of the two electrons in the H-H bond in H2)