e. The third period contains only eight elements even through the electron capacity of the third shell is 18 .

Question

7. Write scientific reasons
e. The third period contains only eight elements even through the electron capacity of the third shell is 18 .

Answer 1

i) The number of elements in the first three periods depends on the electron capacity of the shells and the law of electron octet.
ii. The electron capacity of third shell is 18. So the third period should actually contain 18 elements. But it contains only 8 elements due to the law of electron octet.