What occurs in a nuclear bombardment reaction?

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

Which best term to describe a chemical reaction that absorbs energy from its surroundings? a.thermal conductor b.thermal insulator c.endothermic d.exothermic