Which of the following is best suited to be counted by moles a. roses in a store
b. books in a library
c. cars in a parking garage
d. grains of sand on the New Jersey coastline

Nickel crystallizes in the face-centered cubic (fcc) lattice. the density of the metal is 8902 kg/m3. calculate the radius of a nickel atom.

Who is better, messi or cristiano, i need this for a chemistry class. asap

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?