The question represents the elements P, Q. R and their atomic numbers.

Answer the following using only the alphabets given — P = 13; Q = 7; R = 10

(i) Which element combines with hydrogen to form a basic gas.

(ii) Which element has an electron affinity zero.

(iii) Name the element, which forms an ionic compound with chlorine.

(i) Q combines with hydrogen to form a basic gas.

(ii) R has electron affinity zero as it's octet is complete and it is a stable element.

(iii) P forms an ionic compound with chlorine as it has +3 valency.