Which of the following statements is true? Elements in the same period have similar properties.
Elements in the same group have the same number of electron shells.
O A molecule must be made of two or more different elements.
The periodic table lists elements in ascending order of atomic numbers.

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol

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.