1. Friction is the ___.

A. amount of air in your tires

B. energy that helps your car stay in motion

C. cost of gas prices

D. resistance of movement between two surfaces in contact

Which factor is likely to impact the possible number of compounds ?

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.

The same side of the moon always faces earth because the