Key terms & definitions

How likely a person believes harm to be; this may differ from a statistical estimate.

A person's judgement of how likely or serious a harmful event is, which may differ from estimates based on scientific evidence.

A proportion expressed out of 100.

A proportion expressed out of 100.

One part in every hundred, calculated by dividing the relevant part by the whole and multiplying by 100.

A proportion expressed out of 100. For example, $25\%=\frac{25}{100}=0.25$.

A number of parts per hundred; for example, 17% means 17 out of every 100.

A value expressed as a number of parts out of 100.

A proportion expressed as a number out of 100.

A proportion expressed out of 100. For example, $25\%=\frac{25}{100}=0.25$.

A proportion expressed out of 100.

The percentage of an element’s atoms that are a particular isotope.

A stacked bar chart in which every bar represents 100% of a group and each section shows a component’s percentage of that group.

The proportion of a compound's total mass contributed by a specified element, expressed as a percentage.

The percentage of a compound’s total mass contributed by a particular element.

The fraction of a whole expressed out of 100; for oxygen in air, it can be estimated from the volume of oxygen removed divided by the initial volume of air.

An increase or decrease expressed as a percentage of the original value.

The change in a quantity expressed as a percentage of its initial value.

The change in a measurement expressed as a percentage of its initial value. For mass, $\text{percentage change} = \frac{\text{final mass} - \text{initial mass}}{\text{initial mass}} \times 100$.

The difference between the new and original values, expressed as a percentage of the original value.

The change in a value expressed as a percentage of its original value.

The change in a value expressed as a percentage of its original value: $\frac{\text{new value}-\text{original value}}{\text{original value}}\times100$.

The mass gained or lost, divided by the initial mass and multiplied by 100.

The change in mass expressed as a percentage of the initial mass: $\frac{\text{final mass}-\text{initial mass}}{\text{initial mass}}\times100$.

A factor used to apply a percentage change: for example, $1.07$ represents a 7% increase and $0.93$ represents a 7% decrease.

A composite bar chart in which each complete bar represents 100%, so segment sizes show proportions rather than original frequencies.

The proportion of a sampled area covered by a feature, such as vegetation, expressed as a percentage.

The proportion of a sampled area occupied by a species, expressed as a percentage.

A decimal factor used to multiply a quantity, such as 1.12 for a 12% increase or 0.88 for a 12% decrease.

The mass of one substance or part expressed as a percentage of the total mass of a sample.