(a) Name the charged particles which attract one another to form electrovalent compounds.

(b) In the formation of electrovalent compounds; electrons are transferred from one element to another. How are electrons involved in the formation of a covalent compound ?

(c) The electronic configuration of nitrogen is (2, 5). How many electrons in the outer shell of a nitrogen atom are not involved in the formation of a nitrogen molecule ?

(d) In the formation of magnesium chloride (by direct combination between magnesium and chlorine), name the substance that is oxidized and the substance that is reduced.

(a) Cation [positively charged] and anion [negatively charged]

(b) In the formation of covalent compounds, the electrons are shared between the combining atoms. Depending on the number of electron pairs shared : bond is single [-], double [=], or triple [≡] covalent.

(c) Two electrons in the outer shell of a nitrogen atom are not involved in the formation of a nitrogen molecule.
Reason — Nitrogen has 5 electrons in the valence shell whereas it forms triple bond to fulfill it's octet and hence, 2 electrons are left in the outer shell of a nitrogen atom which are not involved in the formation of a nitrogen molecule.

(d) Magnesium is oxidized and Chlorine is reduced.
Reason — In the formation of magnesium chloride the reaction is :

Mg + Cl₂ ⟶ Mg²⁺ + 2Cl^-

Oxidation : Mg ⟶ Mg²⁺

Reduction : Cl₂ ⟶ 2Cl^-