# Calcium carbonate has the formula CaCO₃. Explain how to calculate the relative formula mass of calcium carbonate, and state its value. (Relative atomic masses: Ca = 40, C = 12, O = 16)

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

## Mark scheme (4 marks)

1. Identifies that the relative formula mass is found by adding together the relative atomic masses of all atoms in the formula
2. Correctly identifies the number of each type of atom: one Ca, one C, and three O atoms
3. Shows correct working: 40 + 12 + (3 × 16)
4. States the correct relative formula mass of 100

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/calcium-carbonate-has-the-formula-caco-af25cf3e) · Published by Druglandscape Ltd.