Metal A has electronic configuration of 2,8,1 and metal B has 2,8,8,2 which is more reactive. Identify these metals and vie their reactions with dil HCl.

Ans. Metal A is Sodium (Na) : 2,8,1

Metal B is Calcium (Ca) : 2,8,8,2.

Metal A (Sodium) is more reactive than metal B (Calcium).

Reaction: -

i.      Sodium metal reacts violently with dilute hydrochloric acid to form sodium chlorides and hydrogen.

2Na_(s) + 2HCl_(aq) → 2NaCl_(aq) + H_2(g)

ii.   Calcium reacts less vigorously to form calcium chloride and hydrogen.

Ca + 2HCl → CaCl₂ + H₂