Key terms & definitions

The acute angle between the final arm of an angle and the $x$-axis.

Data obtained from a known substance and used for comparison with an unknown sample.

A guide used on food labels to show how much a portion contributes to an adult's daily energy or nutrient allowance.

A guideline amount of energy or a nutrient for an average adult, used on labels to show how a food contributes to daily intake.

A fixed line used to guide measurement, positioning or alignment, such as a centre line or grain line.

The daily amount of a nutrient sufficient to meet the needs of nearly all people in a particular population group.

A nutritional reference value indicating an intake sufficient to meet the needs of nearly everyone in a particular population group.

A fixed location used as the starting point for measurements or to align components, such as a notch on a textile pattern.

A group whose measurements provide the values used for comparison on a percentile chart.

An accepted market price used as a starting point when agreeing the price of a particular material or product.

The distinctive result produced by a known substance and used to help identify it.

An existing publication, record or database used to obtain secondary data.

A spectrum from a known substance, used to identify substances in an unknown sample by comparison.

A substance or result with known properties that is used for comparison with an unknown sample.

A known substance used for comparison when identifying an unknown substance.

A surface used as a consistent basis for positioning or measuring material and components.

A trusted value for a known substance, used for comparison with an experimental result.

A vote in which the electorate decides directly on a particular proposal.

A vote in which the electorate decides directly on a particular question rather than choosing representatives.

Changing a program to better meet its requirements, for example by correcting behaviour, completing functionality or improving readability.

The removal of impurities from a material to make it suitable for use.

The ray that travels away from a surface after reflection.

A wave returned when it meets a boundary or surface rather than continuing through it.

The change in direction of a wave at a boundary so that it travels back into the medium it came from.

The return of a wave from a boundary into the medium it came from.

A transformation that produces a mirror image of a graph in a specified line, such as the $x$-axis or $y$-axis.

Thoughtful consideration of an experience, including what it meant and how the writer’s understanding or feelings have changed.

Reviewing your experiences to identify what you learned and how you could improve.

A shape's property of matching itself when reflected in a mirror line.

A rapid, involuntary response to a stimulus.