Q: Given a scientific passage and an answer, generate a question for the given answer.
Passage: Normally, electric charge is transferred when electrons leave the outer orbits of the atoms of one body (leaving it positively charged) and move to the surface of another body (causing the new surface to gain a negative net charge). In a plasma all electrons are stripped from the atoms, leaving positively charged ions and free electrons. Answer: matter in a sample
A:
What do extensive properties depend on the amount of?