Calculate the pOH if the hydrogen ion concentration is 5.7 x 10-3 mol/L

When you mate two plants together the terms is called? answer it fast as possible plz! i have a test tomorrow!

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?

Classify this reaction: 2al+n2-> aln.