If an element has 3 valance electrons what row is it in?

The crust of earth may a- continets and ocean floors. b-continents only. c-layers of sedimentary rocks and continents. d-all of the above

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

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?