Why is pure oxygen called O2 when oxygen is an element?
Exactly as the title asks.
Pure oxygen is generally represented as O2 yet oxygen is an element of the periodic table. Why is it O2 and not just O?
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Exactly as the title asks.
Pure oxygen is generally represented as O2 yet oxygen is an element of the periodic table. Why is it O2 and not just O?
The stuff around us is made out of molecules. Most molecules are made out of more than one atom. Oxygen, the gas, is made out of oxygen molecules. An oxygen molecule is made out of two oxygen atoms. So O2. When you hear "pure oxygen", it's about the substance oxygen (O2), as in pure from other găsesc, not the element oxygen (O).
Now you can also have O or O3 molecules, but those have an electric charge (aka ions), so they're unstable and prone to bond with other elements or to break apart. A gas made out of monoatomic oxygen would be extremely reactive.
Small addition: I wouldn't call O3 (Ozone) charged. It "only" has some partial charge like water (H2O) does, but overall it has the same number of protons and electrons.
Now you could have ozonide (O3-), but that's definitely a way more rare case.
Yeah, I was too lazy to find a better description for it and didn't want to go into valences