Question

Ionic bonds are formed between atoms of elements with electronegativity difference:

• A. greater than 1.9
• B. less than 1.9
• C. greater than 1.3
• D. less than 1.3

Answer 1

The correct option is A greater than 1.9

Electronegativity is defined as the ability of an atom to attract the shared pair of electrons in a molecule. Ionic bonds are formed between atoms of elements with electronegativity difference greater than 1.9.

For example in sodium fluoride:
Electronegativity of sodium is 0.93
Electronegativity of fluorine is 3.98
Electronegativity difference between sodium and fluorine = 3.98 - 0.93 = 3.05 > 1.9

So sodium fluoride is an ionic compound.