OCR GCSE Chemistry A key terms

A smooth line or curve that represents the overall pattern of experimental data without necessarily passing through every point.

A drawing convention in which an ordinary line represents a bond in the plane of the page, a solid wedge points towards the viewer and a dashed wedge points away.

A plotted mark representing one pair of values from a results table.

A place to the right of the decimal point. Decimal places are counted from the decimal point, not from the first non-zero digit.

The number of digits written after the decimal point.

A sign of poor plant growth caused by an insufficient supply of a needed nutrient.

The fraction or percentage of acid particles that form ions when the acid dissolves in water.

An electron that is not confined to a bond between two particular atoms and can move through a structure.

The amount of mass in a given volume of a material; a lower-density material can make a product lighter.

The factor measured or observed in response to changing the independent variable.

The removal of dissolved salts from salty water.

The product that the reaction is being used to make.

A particle or molecule made from two atoms; elemental halogens exist as diatomic molecules such as $Cl_2$.

A molecule containing two atoms, such as O₂ or Cl₂.

An acid solution containing a relatively small amount of acid compared with the amount of water.

A solution containing a relatively small amount of dissolved acid per unit volume.

A measurable extent of an object, such as its length, width or diameter.

A relationship in which multiplying one quantity by a factor multiplies the other quantity by the same factor; its graph is a straight line through the origin.

A relationship in which one quantity is always a constant multiple of another, so $y/x$ is constant and $y=kx$.

The gain or loss of electrons by an ion at an electrode, producing a different substance.

A reaction in which a more reactive element takes the place of a less reactive element in a compound.

A formula that uses element symbols and lines to show which atoms are joined by covalent bonds.

The liquid collected after vapour has condensed during distillation.

A method of separating and collecting a liquid by vaporising it and then condensing the vapour.

The way a substance divides itself between the mobile and stationary phases according to its relative attraction to each one.

A diagram that uses different symbols, usually dots and crosses, to show the outer-shell electrons involved in bonding.

A representation that uses different symbols, usually dots and crosses, to show the origins and arrangement of outer-shell electrons.