Answers

2016-02-25T17:42:20+05:30
The number of elements in the first period are 2. (This period is hence known as a short period.) (2 s-block elements)
The number of elements in the second period are 8.( 2 s-block elements and 6 p-block elements)
The number of elements in the third period are 8. ( 2 s-block elements and 6 p-block elements)
1 5 1