How are all paths that have displacement of zero similar

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true

Nonpoint source pollution is difficult to control because it

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.