Question

A polar covalent bond is likely to form between two atoms that

a. are similar in electronegativity

b. are of similar size

c. differ in electronegativity

Answer 1

A polar covalent bond is likely to form between two atoms that differ in electronegativity, resulting in an unequal sharing of electrons and a molecule with a partial negative and positive charge.

Step-by-step explanation:

A polar covalent bond is likely to form between two atoms that c. differ in electronegativity. This is because, in a polar covalent bond, one atom has a greater attraction for the electrons than the other atom. If the relative attraction, or electronegativity, of an atom for electrons is significant enough to create an unequal sharing of electrons, the result is a polar covalent bond with one end of the bond having a slight negative charge and the other end having a slight positive charge.

For example, in a water molecule, the oxygen atom is more electronegative than the hydrogen atoms, resulting in a polar covalent bond where the shared electrons spend more time closer to the oxygen nucleus, giving it a slightly negative charge and leaving the hydrogen atoms with a slightly positive charge.

Answer 2

c. differ in electronegativity

Step-by-step explanation:

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.

The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive . The bond is polar.

When the elctronegativity difference is 0.4 or less than 0.4 the bond is non polar.

if the electronegativity difference is greater than 0.4 the bond is polar.