Question

If one material has a higher density than another, must the molecules of the first be heavier than those of the second? Explain.

Short answer

No. For a material to be denser, it need not be heavier.

Step-by-step solution

Understanding the concept of density.

The expression to find density is given by:

In other words, it can be said thatdensity is the mass occupied per unit volume.

Analysis of the situation and conclusion

If a body has more molecules in its unit volume, its density will be higher.

For example, consider two bodies. Let the first body have lighter molecules and the second body has heavier molecules. Assume that the molecules are tightly packed in the first body and loosely packed in the second body.

When you consider the molecules for the same volume for two bodies in the above example, the first body with lighter molecules will have a more significant number of molecules, making its density higher than the second body.

So, a body doesn't need to have heavier molecules to be denser