# How can I raw dots-and-crosses diagrams (showing outer electrons only) for ammonia, NH_3?

Jun 26, 2015

You draw intersecting circles with the dots and crosses in the intersections.

#### Explanation:

Nitrogen ($\text{N}$) is in Group 15, so it has 5 outer electrons. It needs three more electrons to complete its octet.

Hydrogen ($\text{H}$) is in Group 1, so it has 1 electron. It needs one more electron to complete its valence shell.

Each atom can get a complete shell if three $\text{H}$ atoms share their electrons and form covalent bonds with an $\text{N}$ atom.

Now, each $\text{H}$ atom has two electrons, and $\text{N}$ has eight electrons in its outer shell.