Question

an ion is an atom with a charge. ions are charged because there is a different number of ______ then protons.
neutrons
protons
electrons
quarks

Explanation:

An atom is neutral when the number of protons (positively - charged particles) is equal to the number of electrons (negatively - charged particles). When an atom gains or loses electrons, it becomes an ion. Neutrons have no charge, so a difference in the number of neutrons from protons does not cause a charge. Protons are already being compared. Quarks are sub - particles that make up protons and neutrons, and their number difference from protons is not the direct cause of an ion's charge.

Answer:

C. electrons