Question

How many groups and periods are there in the modern periodic table? How do the atomic size and
metallic character of elements vary as we move:
(a) down a group and
(b) from left to right in a period.​

Answer 1

Answer:

there are 7 periods and 18 groups in modern periodic table.

down the group atomic size increases, from left to right atomic size decreases.

down the group metallic character increases, from left to right metallic character decreases.