Chemistry Review

Atom
The smalles unit of any living or nonliving thing.
Protons
POsitively charged particles found in the nucleus of the atom.
Electrons
Negatively charged particles that orbit the nucleus of the atom.
Neutrons
Particles with no charge found in the nucleus of the atom.
Element
A substance that consists of atoms with the same chemical properties. classified as atoms with the same number of protons.
Molecule
Two or more atoms bonded together; also called a compound.
Macromolecule
A large molecule (e.g. DNA, hemoglobin)
Ion
A positively or negativley charged atom or molecule; an atom or molecule that has had electrons added or taken away.
Electrolyte
A substance that releases ions when put into a solution; electrolytes are necessary for the proper functioning of all cells in the body; some of the more important electrolytes are: Sodium (Na), Potassium (K), Chloride (Cl), Magnesium (Mg), Calcium (Ca), Iodine (I)
Mixture
A combination of two or more substances.
Solution
A homogeneous mixture of a substance of smaller abundance (solute) dissolved into a substance fo greater abundance (solvent).
Solute
The dissolved substance (e.g. salt, sugar)
Solvent
The dissolving substance (e.g. water)
Suspension
A mixture of two or more substances in a liquid that do not disolve but distribue evenly thorughout the liquid (e.g. India ink, blood)
Acid
A substance that releases hydrogen ions in a solution.
Base
A substance that accepts or binds to hydrogen ions in a solution.
pH scale
The scale from 0-15 used to measure acidity and alkalinity.
Buffer
Any substanc ein a solution that prevents sharp changes in pH.