OCR GCSE Combined Science B key terms

A long nerve-cell fibre that carries electrical impulses away from the cell body.

A chemical equation with the same number of atoms of each element on both sides of the reaction arrow.

A representation in which spheres stand for atoms and sticks stand for bonds, making the arrangement of atoms in three dimensions easier to see.

A graph with separate bars used to compare categories or distinct values.

A contraceptive method that physically prevents sperm from reaching an egg.

The rate of chemical reactions in the body when it is at rest.

The unit of activity: an activity of 1 Bq means one nuclear decay per second.

A fast-moving electron emitted from a nucleus when a neutron changes into a proton during beta-minus decay.

A systematic distortion in data collection or selection that can make results unrepresentative.

A compound containing just two elements joined by ionic bonding.

Capable of being broken down by microorganisms.

The variety of living organisms, including the diversity of species, genetic variation within species and the diversity of ecosystems.

A fuel made from recently living biological material, such as plant crops or wood.

The use of bacteria to help release metal ions from ores into a solution, from which the metal can be recovered.

Using another organism, such as a predator of an insect pest, to reduce pest numbers.

The mass of living biological material.

A living component of an ecosystem, such as a plant, animal or microorganism.

An influence involving living organisms, such as competition, predation or disease.

The amount of glucose in a given volume of blood.

The temperature at which a liquid boils at a specified pressure.

The mean energy needed to break one mole of a particular type of bond, usually given in $\text{kJ/mol}$.

The distance a vehicle travels from when braking begins until it comes to rest.

A substance's tendency to crack or shatter rather than bend when a force is applied.

A solution that resists changes in pH.

A property of a substance that arises from many particles acting together, rather than a property of an individual particle.

An estimate of risk based on evidence, such as observations, measured exposure and the frequency of harmful outcomes. It may still contain uncertainty.

A non-communicable disease in which changes in a cell’s DNA lead to uncontrolled growth and division.