3.3a In all chemical reactions there is a conservation of mass, energy, and charge.

3.3b In a redox reaction the number of electrons lost is equal to the number of electrons


3.3c A balanced chemical equation represents conservation of atoms. The coefficients

in a balanced chemical equation can be used to determine mole ratios in the reaction.

3.3d The empirical formula of a compound is the simplest whole-number ratio of

atoms of the elements in a compound. It may be different from the molecular formula,

which is the actual ratio of atoms in a molecule of that compound.

3.3e The formula mass of a substance is the sum of the atomic masses of its atoms. The

molar mass (gram-formula mass) of a substance equals one mole of that substance.

3.3f The percent composition by mass of each element in a compound can be

calculated mathematically.