Plz hurry!! When an electron moves from a lower to a higher energy level, the electron
A absorbs a continuously variable amount of energy
B always doubles its energy
C moves closer to the nucleus
D absorbs a quantum of energy

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.