Question

1. how is heavy water different from normal water?

an oxygen atom in heavy water has an extra proton.
a hydrogen atom in heavy water has an extra neutron.
an oxygen atom in heavy water has an extra neutron.
a hydrogen atom in heavy water has an extra proton.

Explanation:

Heavy water (\(D_2O\)) has deuterium (\(D\)) instead of normal hydrogen (\(H\)). Deuterium is an isotope of hydrogen with one proton and one neutron (while normal hydrogen has one proton and no neutrons). So the difference is in the hydrogen atom having an extra neutron.

Answer:

A hydrogen atom in heavy water has an extra neutron.