What is the main difference between an atom and an ion? Provide an example of each.

An atom is an electrically neutral particle, meaning it has an equal number of protons and electrons. For example, a neutral Oxygen atom (O) has 8 protons and 8 electrons. An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a net electrical charge. For example, an Oxide ion (O2-) has 8 protons and 10 electrons (gained 2 electrons), and a Sodium ion (Na+) has 11 protons and 10 electrons (lost 1 electron).