I need help with my chemistry hw (questions 3-7)

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?

When water dissolves sugar, which process is not involved? o dissociation o hydration o surface area of the solute increases sa

At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?