What does it mean if an atom has an equal number of protons and electrons?

When an atom has an equal number of protons and electrons, it means that the positive and negative charges are balanced. Protons, which are positively charged, and electrons, which are negatively charged, will cancel each other out when they are present in equal numbers. This results in the atom having no overall charge, making it neutral.

In a neutral atom, the positive charge of the protons is exactly counteracted by the negative charge of the electrons. This fundamental concept is important because it explains how atoms interact with one another and form molecules. Understanding the charge balance helps clarify numerous chemical behaviors, such as how ions are formed when atoms gain or lose electrons and how atoms bond in compounds.