How many electrons will a calcium atom (Ca) lose in order to get a noble gas configuration?

1 Answer
Oct 5, 2014

Calcium atoms will lose two electrons in order to achieve the noble gas configuration of argon. A neutral calcium atom has 20 electrons, while a calcium atom that has lost two electrons will have 18 electrons, and a neutral argon atom also has 18 electrons.

A neutral calcium atom, #""_20"Ca"#, has 20 electrons with an

electron configuration of #"1s"^2"2s"^2"2p"^6"3s"^2"3p"^6"4s"^2#.

An calcium cation, #""_20"Ca"^(2+)#, has 18 electrons with an electron

configuration of #"1s"^2"2s"^2"2p"^6"3s"^2"3p"^6#.

A neutral argon atom, #""_18"Ar"#, has 18 electrons with an electron

configuration of #"1s"^2"2s"^2"2p"^6"3s"^2"3p"^6#, the same as a #"Ca"^(2+)# cation.