Alfred Wegener came up with the idea
The atomic number of H2O is 18 hence it contains 18 protons. Hope this helps.
<span>There are three different subatomic particles present in the atoms of each element: neutron, proton and </span>electron<span>. It is the </span>electrons<span>, and more specifically the valence </span>electrons<span>, that determine the reactivity of an element.</span>
