Which type of rock is formed from existing rock or organisms?

How many grams of n2h4 will be consumed by 23 g of n2o4

Chemical kinetics what was the rate of reaction in trial 3? choose the closest answer.

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?