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.

How many groups and periods are there in the modern periodic table? Ho

1.	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.
Answer» Solution :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.