Difference between compound and bond? (ex. ionic compound vs bond)

Which of the following is a compound? a.carbon b.oxygen c.hydrogen d.water

Fossil fuels are organic compounds that are made from

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.