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Density questions appear in almost every paper. Examined in Edexcel 1PH0/2 (Paper 2). CP7 (Investigating the density of solids and liquids) is a Core Practical on Edexcel — expect questions that directly test your knowledge of the displacement method and sources of error. Edexcel also uses context-based questions involving material properties (e.g. why aluminium is used in aircraft, why wood floats).

• Calculation questions (2-3 marks): Given mass and volume, calculate density. Or given density and one other quantity, find the third. Always show units clearly — kg/m³ or g/cm³.
• CP7 Required practical questions (3-4 marks): Describe how to measure density of a regular or irregular object. Include: measure mass with balance, find volume (geometry or displacement), calculate ρ = m/V.
• Explain floating/sinking (2 marks): Compare the density of the object to the density of water/fluid. State whether it is greater or less, and the consequence.
• Unit conversion: Examiners sometimes mix kg/m³ and g/cm³. Know that 1 g/cm³ = 1000 kg/m³.
• "Suggest" questions (Edexcel): Given an unusual material or object, suggest why it floats or sinks — apply ρ = m/V reasoning to the context.