Refer the above part periodic table and answer the following questions
Write the electronic congiuration of the elements B and E .

Explanation

Electrons configuration of B is `1s ^(2) 2s ^(2) 2p ^(6) 3s ^(2) 3p ^(1) .` Because the element belongs to 13 th group its general configuration is `ns^(2) np ^(1) ` and the element belongs to third period and its atomic number is 3 . Similarly electronic confiuration of E is `1s ^(2) 2s^(2) 2p ^(6) 3s 3p ^(4) ` . Because the element belongs to 16 the group . its general configuration is `ns^(2) np ^(4 ) ` and third period . So its atomic number is 16 .