# How can I write the formula for lithium oxide?

May 30, 2014

This should be straightforward for you :)

Lithium has one valence electron because it appears in group one of the periodic table. Oxygen has two valence electrons because it appears in group six of the periodic table.

This means that Lithium can bond once, and Oxygen can bond twice.

Because Lithium can only bond once, if one atom of lithium were to bond with Oxygen, there would still be one free electron which needs to be bonded. The solution to this is for another Lithium atom to bond with the final free Oxygen electron. So, two Lithium atoms and one Oxygen atom creates:

$L {i}_{2} O$

Hope this helps! :)