A sodium atom loses one electron. What is the resulting charge?

• A. -1
• B. 0
• C. +1
• D. +2

Answer: (C)

When an atom loses electrons, it becomes positively charged because the nucleus still has protons but there are fewer electrons to balance them. The charge equals protons minus electrons. Sodium has 11 protons; a neutral sodium atom also has 11 electrons. If it loses one electron, it has 10 electrons remaining. So the net charge is 11 − 10 = +1. Hence the resulting charge is +1.