When electromagnetic radiation interacts with atoms, energy is absorbed through the electrons. the energetic electrons exhibit and move from the normal low energy level, or , to a higher energy level called the . the energetic electrons do not have enough energy to stay in the higher energy level permanently. as the electrons move from the higher energy level to the lower energy level, they release energy and occurs. energy is released only in specific amounts. the available transitions for each element results in a signature spectra rather than a spectra.

Asolution contains 180 g of glucose (c6h12o6) and 162 g of water. what is the mole fraction of glucose?

1. list three scientific reasons cockroaches may fly.

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.)