There can be three equivalent best resonance structures of . a. NO2
b. NO3
c. SO32-
d. SO42-
e. BrO3-

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.

Using the periodic table, complete the following. element: hydrogen symbol: h₂ molecular weight: g mass of one mole: g/mol

Apropane torch is lit inside a hot air balloon during preflight preparations to inflate the balloon. which condition of the gas remains constant