What is the noble gas notation for magnesium?

1 Answer
Jul 10, 2014

The noble gas configuration of magnesium is [Ne]3s².

You can learn about noble gas configurations at

http://socratic.org/questions/how-can-i-write-a-noble-gas-shorthand

In your problem, you count backwards from magnesium in the Periodic Table until you come to a noble gas.

You come to neon, element 10.

Magnesium is element 12. It has two more protons (and two more electrons) than neon.

The s orbitals fill first.

Magnesium in Period 3, so the electrons go into the 3s orbital.

The noble gas configuration of magnesium is [Ne]3s².