Mar 2, 2026 · Chemistry is the science of the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is …

CHEMISTRY meaning: 1 : a science that deals with the structure and properties of substances and with the changes that they go through; 2 : the structure and properties of a substance the way a …

Jan 19, 2026 · Mole, standard unit (6.02214076 x 10^23) in chemistry for measuring large quantities of very small entities such as atoms, molecules, or other specified particles. The number of units in a …

Feb 6, 2026 · Solvent, substance, ordinarily a liquid, in which other materials dissolve to form a solution. Polar solvents (e.g., water) favor formation of ions; nonpolar ones (e.g., hydrocarbons) do not. …

energy levels for hydrogen The energy-level diagram for hydrogen shows the energy levels, or energy states, as horizontal lines. N = 1 is the ground state of the atom. All other values of N represent …

Feb 10, 2026 · Chemical compound, any substance composed of identical molecules consisting of atoms of two or more chemical elements. All the matter in the universe is composed of the atoms of …

Feb 10, 2026 · Buffer, in chemistry, solution usually containing an acid and a base, or a salt, that tends to maintain a constant hydrogen ion concentration. Ions are atoms or molecules that have lost or …

Mar 2, 2026 · Solution, in chemistry, a homogenous mixture of two or more substances in relative amounts that can be varied continuously up to what is called the limit of solubility. The term solution …

Catalyst, in chemistry, any substance that increases the rate of a reaction without itself being consumed. Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions. In …

Mar 12, 2026 · protein, highly complex substance that is present in all living organisms. Proteins are of great nutritional value and are directly involved in the chemical processes essential for life. The …