Can someone help with this? Sam was given the following equation to balance: H2O → H2 + O2. She balanced it as follows: 2 HOH2 + O2. What did she do wrong? What is the correct way to balance the equation?​

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.