2. In the preceding diagram, label the rock layers X, Y, and Z, making X the oldest layer and Z the youngest. What can you say about the relative ages of fossils found in each layer?

Help please !

If a || b and e || f, what is the value of y ?

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?

Consider the directing effects of the substituents on salicylamide and predict the possible structures of the iodination products. which do you think will be the major product?