Calculate the atomic mass of nitrogen if the two common isotopes of nitrogen have masses of 14.003 amu (99.63% abundance) and 15.000 amu (0.37% abundance).

An electrons position cannot be known precisely only it's probability of being in a certain location can be known

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.)

Fossil fuels are organic compounds that are made from