How can a chemical reaction be compared to shuffling a deck of cards?

Summarize possible ways in which phases of matter could combine to form a solution.

Name the element in group 17, period 2. (periodic table)

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?