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 ?
(i) down a group and
(ii) from left to right in a period.

Explanation

There are 18 groups and 7 periods in the modern periodic table.
(i) Atomic size generally increases down a group due to the addition of new shell and metallic character also increases down a group due to the increase in tendency to lose electrons.
(ii) Atomic size goes on decreasing along a period from left to right. Metallic character decreases along a period due to decrease in tendency to lose electrons.