"Oxygen atoms" refers to individual particles that make up the element oxygen. Oxygen atoms are the building blocks of oxygen gas and are crucial for supporting life and combustion. Full definition
The next oxygen atom in moves just far enough away to get electrons from untouched atoms. (pnnl.gov)
That's because sequential rings of oxygen atoms exactly match the size, and balance the charge, of potassium ions. (sciencemag.org)
When the platinum nanoparticles catch molecules from the surrounding gas and combine them with oxygen atoms from the iron - oxide surface, a surplus of iron atoms remains. (sciencedaily.com)