Hey, guys. Hopefully, you're able to figure this one out on your own. So in this problem, we're asked what the total charge of an atom is. We're told the amount of protons and the amount of electrons. So let's go ahead and use our charge equation. So we know that charge is equal to the number of protons minus the number of electrons, and we're going to multiply that by the elementary charge. So the total charge should be, we've got 16 protons minus 7 electrons, and that's a 7 right there. And we're going to multiply by the elementary charge, which is 1.6 times 10 to the minus 19. You're going to need to remember that number, so go ahead and commit it to memory right now.
So we've got $$\mathbin{\text{$$q = (16 - 7) \times 1.6 \times 10^{-19} $$}}= 9 \times 1.6 \times 10^{-19},$$ and that's a total charge of $$\mathbin{\text{$$1.44 \times 10^{-18}$$}}$$ coulombs. That's the total amount of charge. And what I want you to do is notice that it's also positive. And that makes sense because we have more protons; there are more protons than electrons, so we should end up with a positive number. Let me know if you guys have any questions.