Hyy Chloe how r u
plz answer my question chloe ​

For which one of the following reactions is the value of δh° rxn equal to δh° f for the product? a. 2 h2 (g) + o2 (g) → 2 h2o (l) b. n2 (g) + o2 (g) → 2 no (g) c. 2 h2 (g) + o2 (g) → 2 h2o (g) d. h2o (l) + 1/2 o2 (g) → h2o2 (l) e. none of the above

How many moles of al3+ ions are in 1.25 moles of al2o3

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?