Question

How many groups and peroids are present in modern periodic table?

Answer 1

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

Answer 2

Answer:

There are 18 groups and 6 periods in modern periodic table

Modem Periodic Table has Periods (rows) and Groups (columns). There are 18 groups and number of  periods can be 1 to 7 in a group.

=> A period shows the energy level or orbit number.

=> First period has only two elements. This is the smallest period.

=. Second and third periods have 8 elements each. These are called small periods.

=> Fourth and fth periods have 18 elements each. These are called long periods.

=>Sixth and seventh periods have 32 elements each. These are called very long periods.

=> Group number of an element is same as the number of valence electrons in that element.

=> Metals are on the left side, while non-metals are on the right side of table.

Noble elements are in the last group of periodic table.