(f) the conventions used for labelling graph axes and table columns.

The idea

Graph axes and table columns must be labelled with the quantity name or symbol followed by a forward slash and its unit, for example time $t$ / s or current $I$ / A. The slash means 'divided by', so the numerical scale shows the value of the quantity divided by its unit. A column heading such as mass $m$ / kg tells the reader that entries are in kilograms. If a quantity is a ratio or has no unit, write 'no unit' or leave the space after the slash empty only when the quantity is dimensionless. For logarithmic axes, label with the quantity and state that the scale is logarithmic. Always include units on both axes and every column, and use the same convention throughout a table or graph to ensure clear communication of experimental data.

What earns the marks

• Labels must show the quantity and its unit separated by a slash, for example speed $v$ / m s⁻¹.
• The slash notation means the numerical value is the quantity divided by its unit.
• Every column in a table and both axes on a graph need a label with a unit.
• Dimensionless quantities should be labelled as having no unit or as a ratio.
• Logarithmic axes must be labelled with the quantity and an indication that the scale is logarithmic.

Common mistakes and how to put them right

• Writing only the unit, such as 'm/s', without the quantity name or symbol.

  Put it right: The label must identify what is being measured, for example speed $v$ / m s⁻¹.

• Putting the unit before the slash, such as 's / time'.

  Put it right: The convention is quantity first, then slash, then unit.

• Omitting units from a table column because the unit is given in the question.

  Put it right: Each column still needs its own unit label.

• Using brackets for units instead of the standard slash notation.

  Put it right: OCR conventions require the slash, such as $F$ / N.

Exam tips

• Check every axis and column against the pattern 'quantity symbol / unit' before finishing an answer.
• If a quantity is a ratio such as efficiency, write 'efficiency' with no unit or state that it is dimensionless.
• For logarithmic scales, write '$\\log_{10} (\\text{quantity} / \\text{unit})$' or state clearly that the axis is logarithmic.
• Use the same unit throughout a column; if you convert units, change the column heading to match.