GCSE Chemistry · key term

Prefix

Definition

A word placed before a unit to show that the unit has been multiplied by a particular power of ten; for example, milli means $10^{-3}$ .

Used by OCR

Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)

Long strings of zeros are difficult to read, compare and enter into a calculator, so scientists use prefixes and standard form to show scale clearly.
Revise: Prefixes and standard form
A word part and symbol that scale a unit by a power of ten; for example, kilo (k) means $10^3$ and milli (m) means $10^{-3}$ .
Revise: Unit conversion

1
Prefix symbols are case-sensitive: write $M$ for mega, $m$ for milli and $T$ for tera.
2
Keep the unit attached to the value throughout your working. A correct number with the wrong prefix or unit does not describe the same measurement.

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GCSE Chemistry · key term

A word placed before a unit to show that the unit has been multiplied by a particular power of ten; for example, milli means $10^{-3}$ .

Used by OCR

Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)

Long strings of zeros are difficult to read, compare and enter into a calculator, so scientists use prefixes and standard form to show scale clearly.
Revise: Prefixes and standard form
A word part and symbol that scale a unit by a power of ten; for example, kilo (k) means $10^3$ and milli (m) means $10^{-3}$ .
Revise: Unit conversion

1
Prefix symbols are case-sensitive: write $M$ for mega, $m$ for milli and $T$ for tera.
2
Keep the unit attached to the value throughout your working. A correct number with the wrong prefix or unit does not describe the same measurement.

Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.