What statement best describes an independent variable?
a. the factor that's not changed by the experimenter and is impacted by the dependent variable
b. the factor that's changed by the experimenter and impacts the constant in an experiment
c. the factor that's changed by the experimenter and impacts the dependent variable
d. the factor that does not change, but impacts the constant in an experiment

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In 2002, the rare earth elements mine in mountain pass, california was closed because

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.