Question

The short periods and the long periods are________

• A. Short periods - 1 and 2 and Long periods - 4 and 5
• B. Short periods - 2 and 3 and Long periods - 5 and 6
• C. Short periods - 2 and 3 and Long periods - 4 and 5
• D. Short periods - 3 and 4 and Long periods - 6 and 7

Answer 1

The correct option is C Short periods - 2 and 3 and Long periods - 4 and 5

Periods 2 and 3 are called short periods because we could find elements with s and p orbitals hence only 8 electrons fit in that where as in case of periods 4 and 5 it has even d orbitals hence more 10 electrons would be there in these periods compared to 2 and 3.

Hence Short periods -2 and 3 with 8 elements each.

Long periods - 4 and 5 with 18 elements each.

Option C is correct.