Pedro uses a bar magnet to pick up a nail. He then touches the tip of the nail to some staples. Why do some of the staples stick to the nail?

The nail and the bar magnet are now both permanent magnets.

ANSWER***The nail has become a temporary magnet, while the bar magnet remains a permanent magnet.

The nail has become a permanent magnet, while the bar magnet has become a temporary magnet.

The nail and the bar magnet are now both temporary magnets.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.