What is similar about the outer shell of electrons in the alkali metals family

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

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?

The number of moles of a given mass of a substance can be found without knowing its molecular formula or molar mass. true false