# Question 8d6f7

Jun 30, 2017

Here's how that happens.

#### Explanation:

Lithium oxide is formed due to the electrostatic force of attraction that exists between the lithium cations, ${\text{Li}}^{+}$, and the oxide anions, ${\text{O}}^{2 -}$.

Lithium is located in group 1 of the Periodic Table, which means that it can complete its octet by giving up its sole valence electron $\to$ a lithium cation is formed in the process.

On the other hand, oxygen is located in group 16 of the Periodic Table, which means that it can complete its octet by taking in $2$ electrons $\to$ an oxide anion is formed in the process.

Now, in order to have a neutral compound, the overall positive charge coming from the cation must be balanced by the overall negative charge coming from the anion.

In your case, you need $2$ lithium cations to balance the overall $2 -$ charge coming from a single oxide anion.

2 * ["Li"]^(+) + ["O"]^(2-) -> "Li"_ 2"O"#

So, you can say that when lithium reacts with oxygen, every oxygen atom will take in two electrons, each provided by a lithium atom.

As a result, two lithium cations and one oxide anion, which represent a formula unit of lithium oxide, will be bonded ionically by the electrostatic force of attraction $\to$ an ionic compound is formed.