Question

Maximum valence of second period element is four” explain.​

Answer 1

Answer:

In the second period, we have 2s and 2p orbitals, which can accomodate a maximum of (2+6)=8 electrons. Hence, maximum number of valence electrons is 8.

Answer 2

Answer:

Maximum valency is 4 in the second-period elements because they have only 2s and 2p orbitals.

Explanation:

• There are 8 elements in the second period of the Periodic table.

• Out of which only two are metal (Li and Be), one is metalloid (B) and the rest are non-metals.

• The general tendency of an element is to get stable, so it either tries to lose an electron or gain an electron.  Elements having 1,2 or 3 valence electrons will try to lose it and hence their valency is less than 4 (as it is easy for them to lose rather than to gain). Elements having 5,6,7 valence electrons will try to gain electrons, so they can maximum gain 3 electrons, and hence again valency is less than 3.

• But elements with 4 valence electrons(C) can either gain or lose according to their need. But losing or gaining 4 electrons requires very high energy so they can not do it practically. So mostly they share 4 electrons and hence their valency become 4 which is the maximum among all 2nd-period elements.

• The 2nd-period elements have only 2s and 2p orbitals so they can't expand also and due to this fact, their maximum covalency is 4.

Due to the above-mentioned reasons, maximum valency is 4 in the second-period elements.