A physical law
The law of conservation of matter
A chemical equation
The number of reactants is equal to the number of products.
The reactants and products are written with the same coefficients.
The same number of atoms of each element is on both sides of the equation.
The solid products weight the same as the reactants.
How stable the compound is
What type of chemical bond it forms
How electrons are arranged
What elements it contains
Oxygen and water
Hydrogen and oxygen
Is less than the mass of the reactants
Always equals the mass of the reactants
Cannot be predicted based on the mass of the reactants
Is twice as great as the mass of the reactants
It usually exists as a diatomic molecule.
Its mass is twice as great as the reactants'.
There are two times as many oxygen atoms as reactant atoms.
Its mass increases by two times as a result of the reaction.
In a chemical reaction, matter is not created or destroyed, but is conserved.
Matter can be created and destroyed but does not change forms.
In a chemical reaction, efforts should be made to preserve rare elements without changing them.
In a chemical reaction, the final mass of the products is always greater than the starting mass of the reactants.
Water freezing into ice
Water evaporating from salt water leaving salt crystals
Dew forming on grass
Rust forming on a car body