What is the formula to calculate the density of a material?

The correct answer is density = mass / volume.

Exam lens: Write the relationship, substitute values only when needed, and finish by interpreting the result. This question asks: What is the formula to calculate the density of a material. The correct response is density = mass / volume, because density links mass and volume, so the answer must preserve which quantity is being calculated. In Density of materials, the marking point should connect directly to describe how to determine the volume of a regular solid using length measurements. If the question includes values, the working must keep the appropriate unit and operation; if it is an explanation, it must name the relevant particle behaviour or energy change. This item belongs to Changes of state and the particle model, so avoid answers that switch to a different quantity, confuse heat with temperature, or describe gas pressure without collisions when collisions are the reason. Checkpoint 71 is distinct because it uses this exact question context and the exam lens rather than a generic particle-model sentence.