Question

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  give  their
reactions  with  dil  HCl.

MSCERT Class 10 General Science Ch8 Understanding Metals and Non Metals

Answer 1

metal B is more reactive Hcl will not react with metals

Answer 2

Solutions 

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(a) + 2HCl(aq)→ 2NaCl(aq) + H2(g)

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

Ca + 2HCl → CaCl2 + H2