Question

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

Answer 1

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

Explanation:

Nitrogen (`"N"`) is in Group 15, so it has 5 outer electrons. It needs three more electrons to complete its octet.

Hydrogen (`"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 `"H"` atoms share their electrons and form covalent bonds with an `"N"` atom.

Now, each `"H"` atom has two electrons, and `"N"` has eight electrons in its outer shell.