Which scenario is an example of the transfer of thermal energy by conduction?

In the first law of thermodynamics, triangle e=q-w, what does q stand for

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.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.