The half-life of a radioisotope is the amount of time it takes for a. half the sample to decay. b. all the sample to decay. c. the age of an artifact to be calculated. d. detectable radiation to be absorbed by a sample.

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.