What is the yellow structure, and what role does it play in a cell

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?

Which of the following are acids or bases? 1. sodium hydrogen 2. barium hydroxide solution 3. carbonate solution

What kind of chemical reaction does the chemical equation sodium + chlorine → sodium chloride represent? a. combustion b. decomposition c. single replacement d. synthesis