Question

Arrange the elements with the atomic numbers 9, 12 and 36, identify the element which is 

(a) highly electro negative 

(b) an inert gas in nature 

(c) highly electro positive in nature. Give reasons also

Answer 1

The electronic configurations of the elements are:- 

Z(9) : 1s² 2s² 2p⁵ 

Z(12) : 1s² 2s² 2p⁶ 3s² 

Z(36) : 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰4s² 4p⁶ 

(a). The element with Z =9 (F), is highly electronegative because it requires only one electron to have the configuration of nearest noble gas element and has also very small size. It is infact, the most electronegative (4.0) in the period table. 

(b). The element with Z= 36 (Kr) is an inert gas element as it has ns² p⁶ electronic configuration. 

(c). The element with Z =12 (Mg) is highly electropositive in nature since by using two valence electrons, it will have the configuration of the noble gas Neon.