What element contains 8 valence electrons and tends not to react with other elements?

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.

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

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering