Percentage by Mass of Elements - AQA GCSE Chemistry Calculation Practice Book

Percentage by mass combines Ar, Mr, and percentage calculations into one multi-step problem. This AQA GCSE Triple Chemistry workbook builds systematic working with 12 scaffolded questions using the EVERY method framework.

The EVERY method breaks each calculation into clear steps: Equation, Values, Enter values into the equation, Rearrange if needed, Your units. Every question has a structured EVERY table for students to complete, building a consistent problem-solving habit. Questions get progressively harder: Q1-3 are straightforward, Q4-6 introduce unit conversions, and Q7-12 require rearranging the formula.

What's inside:

- 12 progressive questions on Percentage by Mass (% mass = total Ar of element / Mr of compound x 100)

- Structured EVERY method table on every question page

- Progressive difficulty: simple substitution, then unit conversions, then rearranging

- Self-assessment tracker with "What made me stuck?" reflection checklist

- Full worked answers for all 12 questions using the EVERY method steps

AQA specification reference: 5.3 Quantitative Chemistry (Triple Chemistry only)

Percentage by mass calculations require students to find the total mass contribution of one element within a compound and express it as a percentage of Mr. Questions progress from simple compounds to fertilisers and minerals with more complex formulae.

Common student mistakes this workbook addresses: using Ar instead of total Ar (forgetting to multiply by the number of atoms), calculating Mr incorrectly before starting the percentage, dividing Mr by Ar instead of Ar by Mr, and not multiplying by 100 at the end.

Suitable for AQA GCSE Chemistry (Triple only, not Combined Science). Works for both foundation and higher tier students.

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