Question

The atomic number of ‘X’ is 17. Predict its (a) valency, (b) formula of halide, (c) type of ion formed, (d) reactivity with respect to the other members of same group. 

Answer 1

‘X’ has atomic number 17 

∴ Electronic configuration → 2, 8, 7 

(a) Valency = 1 

(b) Formula of halide = HX 

(c) Type of ion formed = Negative ion (Anion). 

(d) Reactivity = Most reactive among those elements which lie below X in a group.