How to find an intercept

How can one distinguish breccia from conglomerate? a. breccia contains angular clasts and conglomerate contains rounded clasts. b. breccia contains rounded clasts and conglomerate contains angular clasts. c. different minerals cement breccia than cement conglomerate. d. breccia contains sand and conglomerate contains silt.

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.

Which of these metals are magnetic?