Question 8 - Past Year - 3 Mark Questions - Chapter 5 Class 10 - Periodic Classification of Elements

An element ‘X’ with electronic configuration (2, 8, 2) combines separately with two radicals, (NO ₃ ) – and (SO ₄ ) 2–.

(i) Is ‘X’ a metal or a non-metal? Write the nature of its oxide.

(ii) Write the formula of the compounds of ’X’ formed by the combination of these radicals. Are these compounds covalent or electrovalent?

Answer

Electronic configuration of X=2,8,2

(i)

Metals lose electrons to become stable(ie., attain noble gas configuration) whereas, non-metals gain electrons to become stable. Metals form basic oxides and non-metals form acidic oxides.

Since X has a tendency to donate 2 electrons in order to become stable, it is a metal. Since X is a metal, the nature of its oxide will be basic.

(ii)

X will react with 2 NO ₃ - radicals because it has 2 electrons for donation to form X(NO ₃ ) ₂

X will react with one SO ₄ ^2- to form XSO ₄

These compounds are ionic or electrovalent.