Answer:
An oxygen atom, O, is a single atom with 8 protons, 8 electrons, and more than likely 8 neutrons (although that can change from isotope to isotope). This single atom is not normally observed, but can be produced in the gas phase at high temperature in a laboratory setting. You can't buy a tank of oxygen atoms. Instead, oxygen is almost always found as O2, the oxygen molecule. This is what we breathe, this is how oxygen normally exists, you CAN buy a tank of O2 molecules. The molecule is formed by two oxygen atoms with a covalent double bond between them, meaning they share 4 electrons so that each has a full octet of electrons.
Explanation:
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