Answer:
melting, freezing, and boiling are physical changes
Explanation:rusting and souring are ex. of chemical, not physical
An insoluble solid formed during a reaction is called a Precipitate.
<span>Mass number is the number of protons and neutrons in an atom, and it tells us about the mass of the atom in amu, or atomic mass units. </span>
<span>Atomic mass is the average mass of all the isotopes of a certain type</span>
Chemical changes are irreversible.
A chemical change that could happen at school would be when you have a chemistry experiment and you mix an acid and a base such as mixing hydrochloric acid with sodium hydroxide.
A chemical change that could happen at home would be baking a cake. You can't take the ingredients used in baking a cake back apart because they have changed their chemical composition.
A chemical change that happens in nature could be a forest fire. The burning of wood would be the chemical change in this case.
12 Oxygen, 2 Aluminum, and 1 Sulfur. let me know if you need anything else.