Question

Why was carbon 12 chosen over oxygen for atomic mass if oxygen was so suitable?

Answer 1

Carbon is an element which can react with more elements than oxygen. Carbon can form very large bonds whereas oxygen cannot since oxygen has 2 valence electrons so it can only react with elements which can give 2 electrons to oxygen.On the other hand, carbon has 4 valence electrons which means Carbon can combine with many more elements by forming covalent bonds.