What volume of solution is required to produce a 7.8M solution containing 23.6g of LiBr?

Compare and contrast physical changes with chemical changes.

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.

Which orbitals form a pi bond? a. the s orbital and three p orbitals b. the s orbital and two p orbitals c. overlapping p orbitals d. overlapping hybrid orbitals