Hi can someone please help me with this I’m so confused.

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?

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

In which reaction is precipitation occurring?