What does a control group show in an experimental investigation? A. the effects that the scientists are causing by manipulating variable? B.
how nature would act without manipulation by the researchers ? C.
why each part of a system is related to every other part ? D.
all parts of a system that scientists are controlling and changing

Which of the following statements are evidence that gases do not always behave ideally? check all that apply.? a. co2 gas becomes dry ice (solid co2) at 1 atm and –78.5 °c. b. when two gases are mixed, they follow dalton\'s law of partial pressures. c. at 4 k and 1 atm, helium is a liquid. d. it is impossible to compress a gas enough so that it takes up no volume.