Thallium-201 has a half-life 73 hours. if 4.0 mg of thallium-201 disintegrates over a period of 5.0 °, how many milligrams of thallium-201 will remain?

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.

At the current rate, a graph of carbon dioxide produced by fossil fuels over time would slope upward slope downward be horizontal be vertical

What is the correct lewis dot structure for arsenic?