Combined Science key terms

A large, repeating arrangement of atoms or ions extending throughout a metal, held together by metallic bonding.

A compound of a metal and oxygen.

A unit of length equal to one millionth of a metre: $1\text{ µm} = 10^{-6}\text{ m}$.

The study of objects too small to see clearly with the unaided eye, using microscopes.

The regular movement of organisms between areas, often at different times of year.

A unit of length equal to $10^{-3}$ metres. Its symbol is mm.

A process in which parts of a dead organism are replaced by minerals as they decay, preserving their shape.

Action that reduces the causes of climate change, for example by reducing greenhouse gas emissions.

A sub-cellular structure where the reactions of aerobic respiration take place, releasing energy for cellular processes.

A type of cell division that produces two genetically identical daughter cells with the same chromosome number as the parent cell.

Two or more elements or compounds together without being chemically combined with one another. Each substance retains its chemical properties.

The phase that moves through the stationary phase and carries dissolved substances; in paper chromatography, this is the solvent.

The value that occurs most often in a dataset.

The mass per mole of a substance, measured in g/mol. Its numerical value equals the substance’s relative formula mass.

The ratio of amounts in moles in which substances react or form, given by the coefficients in a balanced chemical equation.

The unit of amount of substance, with symbol mol. One mole contains $6.02 \times 10^{23}$ specified particles.

A formula showing the number of atoms of each element in one molecule.

A group of atoms held together by covalent bonds.

The ratio of the amounts, in moles, of two substances in a reaction, given by their balancing numbers in the balanced symbol equation.

Melted into the liquid state.

The property of a moving object calculated using $p = mv$, where mass is measured in kilograms and velocity in metres per second. Momentum has a direction and is measured in kg m/s.

Existing as single atoms rather than atoms bonded together in molecules.

The growing of only one type of crop in an agricultural area.

The inheritance of a characteristic controlled by a single gene.

The force experienced by a current-carrying conductor placed in a magnetic field.

A neurone that carries electrical impulses from the central nervous system to an effector.

Methicillin-resistant Staphylococcus aureus: a strain of bacteria resistant to several antibiotics and therefore difficult to treat.