The law of conservation of mass
the total mass of the products of a reaction equal to the total mass of the reactants atoms cant be created or destroyed
Why do we balance chemical equations
during a chemical reaction atoms of the reactants are rearranged to form products but the atom stays the same
How to know a chemical change happend
energy is released/consumed
unexpected colour changes
a gas is produced (new odour)
a precipate forms
Experiment that can prove reactivity of metal
Be able to compare the reacitivity of the metals the one that has a reaction means that metal is more reactive