Question

How does number of (i) valence electrons (ii) valency;
vary on moving from left to right:
(a) in the second period of a periodic table ?
(b) in the third period of a periodic table ?
​

Answer 1

Answer:

Across the period the valence electrons or number of electrons in the last shell increases from group 1-2 and then from 13 to 18. -In the second period, the last shell electrons enter into the n=2 shell. Thus the valence electrons increase from lithium to the neon.