Edexcel GCSE Combined Science key terms

The point beyond which force and extension are no longer directly proportional.

Indicator paper that is red in acidic conditions and blue in alkaline conditions; damp litmus paper is bleached white by chlorine.

The mains wire that carries the alternating potential difference from the supply to an appliance.

A pair of outer-shell electrons that is not shared in a covalent bond.

A wave in which vibrations are parallel to the direction of energy transfer.

An energy source that produces relatively little greenhouse gas emission per unit of energy supplied, taking account of its production and use.

An ore containing a relatively small proportion of the useful metal.

A substance that reduces friction between surfaces moving past one another.

The use of a substance such as oil or grease between moving surfaces to reduce friction and unwanted energy transfer.

The internal space of a blood vessel through which blood flows.

A white blood cell that produces antibodies to help destroy pathogens and antitoxins to neutralise their toxins.

An enzyme found in tears that breaks down and kills bacteria on and around the eyes.

A region in which a magnet, magnetic material or current-carrying conductor can experience a magnetic force.

A measure of magnetic field strength, represented by $B$ and measured in tesla (T). A field of 1 T exerts a force of 1 N on a 1 m conductor carrying 1 A at right angles to the field.

A material that is attracted to a magnet and can become magnetised, such as iron, steel, cobalt or nickel.

One of the two regions of a magnet, called north and south, where its magnetic effect is strongest.

The factor by which an image is larger than the actual object: $\text{magnification}=\text{image size}\div\text{actual size}$.

The size of a quantity, without its direction.

The ability of a material to be hammered or bent into a different shape without breaking.

Poor nutrition resulting from an insufficient, excessive or unbalanced intake of nutrients.

A measure of the amount of matter in an object, measured in kilograms (kg). Moving the object to a different gravitational field does not change its mass.

The total number of protons and neutrons in a nucleus, represented by $A$. Also called the nucleon number.

A substance used to treat a disease or relieve its symptoms.

A substance through which a wave travels, such as air, water or glass.

Cell division that produces four genetically different haploid daughter cells, each with half the original number of chromosomes, for sexual reproduction.

The temperature at which a substance changes from solid to liquid.

A long-lived lymphocyte formed during an immune response that enables a faster response to later exposure to the same antigen.