Which statement is true if the delta h of a reaction is positive

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

How do cfcs cause ozone depletion? how do cfcs cause ozone depletion? ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule.

What are the two basic types of satellites