Given a scientific question, generate a correct answer to it.

Input: Consider Input: What third property is different if two boxes have the same volume but one has greater mass?

Output: density

Input: Consider Input: Many microorganisms are single celled and use what for perception and movement?

Output: organelles

Input: Consider Input: Radiation can be absorbed or shielded by materials, particularly what material used to make protective aprons worn by x-ray administrators?
Output: lead