Total number of ground in Mendeleef's table

Number of short periods in Mendeleef table

Anamalous pair in Mendeleef's table is

Write the total number of periods in modern periodic table.

The total number of unpaired electrons present in phosphorus in ground state is:

4.What is the total number of s-electrons in the electronic configuration of arsenic (As) atom in the ground state - (Atomic no.of As "=33" )

Which of the following elemts will have the same total number of electrons in 's' as well as 'd' subshells in the ground state electronic configuration