Question

Given on the side is a part of the periodic table.

Arrange the given elements;

In the order of increasing nonmetallic character in the

Period -

Group -

Answer 1

1. The elements have the tendency to gain $e^{-}$to obtain noble gas configuration. The non-metals have this tendency.
2. This property of gaining $e^{-}$ and forming negatively charged is known as non-metallic property. It is easier for an element to gain one valence electron as compared to gaining $2$ or $3$ valence electrons.
3. Also, it is easier for small species to gain electrons more easily and there is more effective nuclear charge.
4. Across a period, the non-metallic character increases as the size decreases and number of valence $e^{-}$ increases. Down the group period, non-metallic character decreases as the size increases.
5. Hence the order of increasing non-metallic character will be:

Group–$Cs<Rb<K<Na<Li<H$

$Ne<He$

Period– $H<He$

$Li<Be<B<C<N<O<F<Ne$