5) Given the Lewis electron-dot diagram:
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H:C:H
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Which electrons are represented by all of the dots?
A)
the carbon valence electrons, only
B) the hydrogen valence electrons, only
C)
the carbon and hydrogen valence electrons
D) all of the carbon and hydrogen electrons

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

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.

Astudent conducts an experiment to determine how the amount of water given to a plant affects its growth. what is the independent variable for this experiment?