Question

An element ‘X’ placed in 2nd group and 4th period of the periodic table burns in the presence of oxygen to form a

basic oxide.

(a) Identify the element

(b) Write its electronic configuration

(c) Write a balanced equation for the reaction when this oxide is dissolved in water.

Answer 1

The name of element 'X' is Calcium as it is in the position of 4th period and 2nd Group in the modern periodic table. The electronic configuration of sodium is 2,8,8,2. The balanced equation is :
2Ca(s)+O2(g)-> 2CaO(s)
CaO is basic in nature. This is an example of combination reaction also. I hope that this will help you a lot.