Which of the following is not true about a pool of water and a piece of ice?

a. they have the same composition.
b. they are in different states of matter.
c. they have different chemical properties.
d. they have different physical properties.

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.