PH
A number describing the concentration of hydrogen ions in a solution.

Phase
A substance with uniform composition and definite physical state.

Polar bond
Atomic linkage with both ionic and covalent characteristics.

Polyprotic
Refers to an acid with several hydrogens that can dissociate.

Precipitate
A solid that separates from solution.

Product
A substance on the right side of a chemical reaction.

Proton
A heavy subatomic particle with a positive charge; found in an atomic nucleus.