Question

The electronic configuration of an element is $1s^2,2s^2,2p^6,3s^2$. The oxidation number of the element in its compounds can be:

• A. $+2$
• B. $+8$
• C. $+1$
• D. $0$

Answer 1

The correct option is A $+2$

The element with electronic configuration $1s^2,2s^{2}2p^6,3s^2$ is magnesium. It has two valence electrons which can be easily donated. Thus it is a bivalent metal and it forms compounds with $+2$ oxidation state.