Calculate the heat of recation for this chemical reaction Al +O2 -> Al2O3?
(its unbalanced).​

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?

Hey can you me with this i really need y’all

The element that has the greatest electronegativity is