Question

The table below gives the numbers of protons, electrons, and neutrons in four atoms.

Atom Number of protons Number of neutrons Number of electrons
1 9 8 9
2 9 9 8
3 9 9 10
4 9 10 9

Based on the table, which atom has a charge of –1?
1
2
3
4

Answer 1

3

Atom 3 has 9 protons and 10 electrons, so it has one extra electron (9 − 10 = −1), giving a −1 charge (F−).