The element germanium is a lustrous, hard, grayish-white solid in the carbon group. it is a semiconductor with an appearance similar to elemental silicon. based on these facts, we should classify germanium as a a) metal b) nonmetal c) metalloid d) rare earth element

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.