Where would a plant that lives on land get nutrients from?

What element breaks down into yttrium-90?

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?

Based on its chemical properties, identify the position of each chemical family on the periodic table.