Which group on the periodic table has
elements with atoms that tend not to bond with
atoms of other elements?
(1) group 1 (3) group 17
(2) group 2 (4) group 18

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?