What problems must be overcome before Fusion can be used to produce energy​

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

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?