Are halogens metals or nonmetals?

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.

What are the similarities between compounds and mixtures?