Which statement is correct for all elements in the same group They have the same number of electrons in the highest occupied energy level
They have the same chemical reactivity
They have the same number of occupied energy levels
They have the same number of neutrons

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.