Question

Calcium is an element with atomic number 20. Stating reason answer each of the following questions : (i) Is calcium a metal or non-metal? (ii) Will its atomic radius be larger or smaller than that of potassium with atomic number 19 ? (iii) Write the formula of its oxide.

Answer 1

(i)Calcium is a metal because it has 2 valence electrons and elements having 1.,2 valence electrons are metallic in nature.

(ii)Its atomic radius will be smaller than that of calcium because it has 2 valence electrons and potassium has 1 valence electrons for which the nuclear charge decreases and atomic radius increases for calcium

(iii)Calcium oxide=  CaO

Answer 2

Calcium is metal

And it's atomic radius is larger

And it's formula for oxide is CAO