Which of the following was not a contribution by niels bohr? electrons are in orbits. there is a relationship between the outer shell and chemical properties. the charge of an electron. quantum energy emissions.

Which statements describe polyatomic ions? check all that apply. polyatomic ions have many charges. polyatomic ions have one overall charge. polyatomic ions repel other ions to form ionic bonds. polyatomic ions attract other ions to form ionic bonds. polyatomic ions are made up of only one type of atom. polyatomic ions are made up of two or more types of atoms.

If an area has high air pressure and low humidity, what type of weather will it most likely have? plz !

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)