Question

what two elements make up water?

1. oxygen and carbon
2. helium and oxygen
3. helium and carbon
4. hydrogen and oxygen

Explanation:

Water has the chemical formula \(H_2O\), which means it is composed of hydrogen (\(H\)) and oxygen (\(O\)) atoms. The other options (oxygen and carbon, helium and oxygen, helium and carbon) do not form water.

Answer:

1. hydrogen and oxygen