At night, there is a drop in the amount of ozone in the upper atmosphere. why does this drop occur?

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?

What happened to the amount of carbon dioxide in the atmosphere from 2010–2017?

What metric units would you use to measure the thickness of a key