Question

Atoms contain charged particles called protons and electrons. Each proton has a charge of +1, and each electron has a charge of –1. A sulfur ion has 16 protons and 18 electrons. Find the net charge.

Answer 1

-2 
16 positive protons + 18 negative electrons

Answer 2

Each proton is has a charge of +1, so you have +16 total for protons
Each electron has a charge of -1, so you have -18 total for electrons
16 + -18 = -2
The net charge is -2.