# Electron Configuration Of Calcium Ion

**Now let's do another example.**

**Electron configuration of calcium ion**.
In writing the electron configuration for calcium the first two electrons will go in the 1s orbital.
The electron configuration for calcium atom (z = 20 ) is 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 4 s 2 ca atom loses two electrons to form c a 2 + ion the electron configuration for calcium ion is 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6
The electron configuration of a neutral calcium atom is :

1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10. There are 118 elements in the periodic table. Calcium has 20 electrons but is in group two so wants to lose 2 electrons.

Hence, the electron configuration for ca 2+ is 1s 2 2s 2 2p 6 3s 2 3p 6. For instance, the ground state electronic configuration of calcium (z=20) is 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2. Hence, the electron configuration for ca 2+ is 1s 2 2s 2 2p 6 3s 2 3p 6.

1s2 2s2 2p6 3s2 3p6 4s2 Since we need to take away two electrons, we first remove electrons from the outermost shell (n=4). 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2.

Both of the configurations have the correct numbers of electrons in each orbital, it is just a matter of how the electronic configuration notation. Just replace this portion of zinc's electron notation with argon's chemical symbol in brackets ([ar].) so, zinc's electron configuration written in shorthand is [ar]4s 2 3d 10. Note that when writing the electron configuration for an atom like fe, the 3d is usually written before the 4s.

To save room, the configurations are in noble gas shorthand. So calcium, let's make it two plus. How many electrons must be lost by the element ca.