Type your answerto chemicals here... add water to chemicals
CO2 or carbon dioxide because a chemical reaction is when two or more elements bond together chemically in this case carbon and oxygen are bonding.
Salt makes the water colder.
Water is made from H20, but it is in a liquid form. Water vapor is also made from H20, but it is in a gas form.
Could be either or both. Depends on the method used to purify the water. If you use reverse osmosis or distillation, it would be physical. If the water is treated with chlorine, it would be chemical.