Question

Q.How do the valency and atomic size of the elements vary while going from left to right along A period and top to bottom in a group in the modern periodic table? (Chemistry Chapter 5 Classification of Elements)​

Answer 1

Answer:

Atomic size decreases on going along a period from left to right because the electron enters into the same shell, therefore, attraction between nucleus and outermost electron increases and thus atomic size decreases. Valency first increases from 1 to 4 and then decreases from 4 to 0 along a period from left to right.