Explain how this chemical melt the ice

The reaction q+r2=r2q is found to be first order in r2 and

What three natural resources are found in the great lakes region

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?