Two chemical reactions are described below.

• Nitrogen and hydrogen react to firm ammonia (NII)

• Carbon and hydrogen bond to form a molecule of methane (NH₃).

For each reaction, give:

(a) The valency of each of the atoms involved in the reaction.

(b) The Lewis structure of the product that is formed.

● Nitrogen and hydrogen react to form ammonia.

(a) The electronic configuration of nitrogen is 1s²2s²2p³. Outermost orbit

contains 5 electrons. So, it needs 3 more electrons to obtain octet. Valency of nitrogen is 3. Electronic configuration of hydrogen is 1s¹. Valency of hydrogen is 1. It need to gain one more electron to obtain stable duplet structure. so, one nitrogen contributes its 3 electrons to 3 hydrogen atoms and each hydrogen contributes its one electron for bond formation. The electrons are shared by both nitrogen and hydrogen. Both become stable and form ammonia.

(b)

● Carbon and hydrogen react to form methane.

C + 2H₂→ CH₄

(a) Carbon has 4 electrons in its outermost orbit. Carbon shares

electrons to obtain octet. It needs 4 more electrons to obtain octet. So, valency of carbon is 4. Electronic configuration of hydrogen is 1s¹. Valency of hydrogen is 1. It need to gain one more electron to obtain stable duplet structure. so, carbon contributes its 4 electrons in bond formation with 4 hydrogen atoms. Hydrogen atoms contribute their one electron. So, these electrons are shared by both carbon and hydrogen to form bonds.

(b)