Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. Answer: a drumlin
[EX A]: What is the name of a long and low hill of sediments which have been deposited by a glacier?

[EX Q]: Passage: Many common electric devices, such as doorbells, contain electromagnets. If they have moving parts, they are likely to have an electric motor. An electric motor is a device that uses an electromagnet to change electrical energy to kinetic energy. Answer: electromagnets
[EX A]: What do electric motors use to change electrical energy into kinetic?

[EX Q]: Passage: All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactive. These isotopes are called radioisotopes . Their nuclei are unstable, so they break down, or decay, and emit radiation. Answer: protons
[EX A]:
All the atoms of a given element have the same number of what in their nucleus, though they may have different numbers of neutrons?