1. The problem statement, all variables and given/known data What happens to a water molecule if it is hit by a high energy electron or photon? 2. Relevant equations 3. The attempt at a solution My knowledge of chemistry is very limited, and my guess is that it would be ionized: [tex] e + H_2 O \rightarrow H^+ + OH + 2e [/tex] Here, a high energy electron hits the molecule and releases 1 electron from the H atom, making it a cation. Two electrons appear in the products: 1 from the H along with the original electron. If something like this were possible, then could a "hydroxide cation" be formed? [tex] e + H_2 O \rightarrow H + OH^+ + 2e [/tex] And if a photon strikes the molecule, how about [tex] \gamma + H_2 O \rightarrow H_2 + O [/tex] (Can water absorb photons?) I am trying to understand how a covalently-bonded molecule "breaks up" when bombarded with cosmic rays, and would like to know if any of these examples (which contain such a molecule) are plausible. Thanks for your help!