# Calcium carbonate has the formula CaCO₃. Define the term relative formula mass and describe the steps a student would take to find the relative formula mass of calcium carbonate, using the periodic table. (Atomic masses: Ca = 40, C = 12, O = 16)

> Pearson Edexcel International GCSE Chemistry (4CH1) — 1.4 Relative formula mass · Define · 4 marks

## Mark scheme (4 marks)

1. Relative formula mass is the sum of the relative atomic masses of all atoms in the formula
2. Identify the number of each type of atom: one Ca, one C, and three O atoms
3. Multiply each element's relative atomic mass by its number of atoms: 40×1, 12×1, 16×3
4. Add all the values together to give a relative formula mass of 100

## Key terms

- [relative formula mass](https://www.gradenine.co.uk/glossary/relative-formula-mass)
- [formula](https://www.gradenine.co.uk/glossary/formula)

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Source: [GradeNine](https://www.gradenine.co.uk/q/calcium-carbonate-has-the-formula-caco-d49c3d61) · Published by Druglandscape Ltd.