By 1999, after the clean water act had been passed in 1970, the percentage of u. s. surface waters safe for fishing and swimming had increased from 36 percent to

Two atoms interact with each other as shown by the equation. complete the equation by filling in the missing parts. 1 2 3 4 5 h he li

Which of these features are formed when hot groundwater is forced out through cracks in the earth's surface?

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.