Question

What do the following abbreviations stand for?

(i) $O$

(ii) $2O$

(iii) $O_2$

(iv) $3O_2$

Answer 1

i) O denotes atom of oxygen.

ii) 2O denotes two atoms of oxygen.

iii) O₂ denotes a molecule of oxygen gas.

iv) 3O₂ denotes three molecules of oxygen gas.