When an atom gains or lose electrons then the atom tends to attain a negative or positive charge. Thus, the ions become charged.
Whereas when an atom is neutral then the number of electrons equals the number of protons. But when an atom becomes charged then the ions have unequal number of protons and electrons.
For example, atomic number of sodium is 11 and when it loses one electron then it attains a positive charge. The equation is as follows.
Thus, we can conclude that ions must always have an unequal number of protons and electrons.
Answer:
Jose and Sarah are running in the cross country meet. Their skeletal and muscular systems work to move them through the course. As they run, they breathe faster and harder and their heart rate increases.