Can anybody please explain how to do this, i’m very confused:( or show me a picture of it, please explain it would be very helpful in doing the other questions myself

b. the carbon cycle ensures living things have a source of hydrogen

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.