Key terms & definitions

A drawing that represents a three-dimensional object using three directions to show its width, depth and height.

A pictorial drawing method that represents three dimensions using a vertical axis and two axes at 30° to the horizontal, with the same scale along each axis.

A drawing that represents a three-dimensional solid using vertical lines and two sets of equally spaced diagonal lines.

A transformation that preserves distances, so the image is congruent to the original. Translations, rotations and reflections are isometries.

Equality before the law for citizens. Maeandrius offered this at Samos but withdrew his offer rather than establishing a lasting alternative to tyranny.

A triangle with at least two equal sides; the angles opposite those sides are equal.

A contraction in which a muscle changes length while producing tension; it may be concentric or eccentric.

A solution in which a potato chip has no overall gain or loss of water by osmosis.

An atom of an element that has the same number of protons as its other atoms but a different number of neutrons.

An atom of an element with a particular number of neutrons in its nucleus.

Atoms of the same element with the same number of protons but different numbers of neutrons.

Atoms of the same element with the same number of protons but different numbers of neutrons.

Atoms of the same element that have the same number of protons but different numbers of neutrons.

The proportion of an element's atoms that are a particular isotope, often expressed as a percentage.

The proportion of atoms in a sample that belong to a particular isotope, often expressed as a percentage.

Israel’s national armed forces, established from the Haganah as the new Israeli state was created in 1948.

The angel who will blow the trumpet to announce the Day of Resurrection.

A narrow strip of land joining two larger land areas, with water on either side.

A Rastafarian approach to food that emphasises natural, clean eating, often based on plant foods and avoiding artificial additives.

The process of repeatedly using the output from one calculation as the input to the next.

The repeated execution of a block of instructions.

Repeated development, testing and improvement of a design.

A rule such as $x_{n+1}=g(x_n)$ that generates each new value from the preceding value.

A process of repeatedly exploring, testing, evaluating and refining a design to improve how well it meets requirements.

A formula such as $x_{n+1}=f(x_n)$ that defines each value from an earlier value.

A process in which stages are repeated and improved in response to what has been learnt.

Repeated testing of modules during program development, using the results to correct and improve the code.

A period of retreat in a mosque devoted to worship, study and reflection, often undertaken near the end of Ramadan.

A travelling preacher who addresses different communities rather than serving only one settled congregation.

An internationally agreed system for naming chemical substances clearly and consistently.