An element with the valence electron configuration 4s24p4 would form a monatomic ion with a charge of fill in the blank 5 . In order to form this ion, the element will ___ electron(s) from/into the subshell(s).

Charge= -2.

Gains two electron into the 4p^4 to become 4p^6.

Explanation:

The element in the periodic table/chart that matches with the valence electron configuration is Selenium with full electron configuration of [Ar] 3d^10 4s^2 4P^4 which is a non-metal that is found in group 4 of the periodic table/chart.

Selenium can receive 2 more electrons on the 4p^4 to give a -2(minus 2) ion that is Se^2-.

Selenium can also loose 2 electron from 4s^2 to give a +2 ion that is Se^2+.

Selenium can also loose 2 electrons from 4s^2 and 2 electrons from 4p^4 to form Se^4+.

Selenium can also loose 2 electrons from 4s^2 and 4 electrons from 4p^4 to form Se^6+.

Thus, in order to form a monatomic ion with a charge(we will be making use of the most stable one). Thus, it will gain two more electron since this is easier to become 4s^2 4p^6.