Under what circumstances will a scientific theory be changed or discarded? a. new experimental evidence is not compatible with the theory. b. many experiments give the results predicted by the theory. c. a scientist makes a hypothesis that contradicts the theory. d. a scientist proposes a competing theory.

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.