Common Misconceptions
Part of Density · GCSE GCSE Physics revision
This common misconceptions covers Common Misconceptions within Density for GCSE Physics. Revise Density in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 8 of 13 in this topic. Use this common misconceptions to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 8 of 13
Practice
13 questions
Recall
30 flashcards
⚠️ Common Misconceptions
Misconception 1: "Heavier objects have higher density"
This is wrong! Density depends on mass AND volume. A large block of polystyrene is heavier than a small steel ball, but polystyrene is far less dense. You can only compare densities when looking at equal volumes of each material.
Misconception 2: "Density changes when you cut a material in half"
No — density is an intrinsic property of a material. Cut a steel bar in half and each half has half the mass AND half the volume. The ratio (density) stays exactly the same: 7800 kg/m³.
Misconception 3: "Gases have no density"
Gases do have density — air is about 1.2 kg/m³. It is much less than liquids or solids, but it is not zero. This is why helium balloons float (helium is less dense than air) and why carbon dioxide sinks (denser than air).
Quick Check: Oil has a density of 900 kg/m³ and water has a density of 1000 kg/m³. What happens when you mix them, and why?
Oil floats on water because oil is less dense (900 kg/m³) than water (1000 kg/m³). Less dense liquids always float on top of denser ones.
Keep building this topic
Read this section alongside the surrounding pages in Density. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Density
What is the correct equation for density?
Explain why gases have a much lower density than solids, using ideas about particles.
Quick Recall Flashcards
13 questions on Density — practise free
Instant marking, adaptive difficulty, and 30 spaced repetition flashcards. Free until your GCSEs.
Try PrepWise Free