You could also ask students to plot a 1D scale on a piece of paper in a 1:2 ratio by drawing a 20 cm line and labelling the two ends 0 and 40, for example. Fraser Scott’s article on choosing appropriate scales provides some excellent guidance and resources on this misconception (rsc.li/2YJDLU9). In chemistry, students can struggle to conceptualise scales as ratios, often drawing non-linear scales and choosing inappropriate scales. Many of the scales students meet in maths are 1:1, allowing them to bypass converting values using ratios. Using y = f(x) to determine y values and plotting on a 1:1 scale grid Maths for ages 11–14 will generally approach graphing from two different angles:ġ. Chemistry lessons remain focused on drawing graphs to represent experimental data, whereas in maths graphs transmute into expressions of mathematical functions. However, approaches to graphing in maths and science diverge at ages 11–14. Students first encounter graphing in primary maths and science: they plot data points on scales and take readings. Their neat, well-drawn graph is your chemical law. Unlike experts, novices don’t automatically see graphs as mathematical objects which can be manipulated logically – they see pictures and representations, rather than tools.

to facilitate the transformation of a conceptual idea into something concrete and memorable.

to illustrate texts and make them more engaging.

to interpret information and manipulate data to make deductions.

In chemistry lessons students will meet hundreds of graphs, of four general types: Students carrying out a graph plotting activity after a practical are far more likely to remember the mechanical practice of drawing scales, plotting points and drawing a line of best fit than the shape of the graph or how this relates to the properties they were investigating. This does not follow for novice chemists. Expert chemists can conceptualise graphs in myriad ways: they can plot results, spot the pattern, and their graph becomes a memory trigger for their findings.

Graphical representations are an intrinsic aspect of the study and practice of chemistry.

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