Answers (6)
"Water molecules can be broken down into hydrogen and oxygen molecules by a chemical reaction called electrolysis. When an electric current is passed through liquid water (H2O), it changes the water into two gases—hydrogen and oxygen. The molecules of water break apart into individual atoms."
Atoms bond to form a new molecule by sharing electrons. That is a chemical change.
When the water changes from a gas to a liquid to a solid, those are physical changes because there is no change in the bonding.
If there is no reaction then what you have is a mixture.
