What is the purpose of a control group within an experiment?

a. to be able to test several different hypotheses at the same time

b. to be able to perform a variety of experiments on the control
group

c. to have a part of the experiment constantly change
d. to identify any differences between the control group and the
experimental group

Put the following steps of the convection process in the correct order. 1. gravity pulls cooler matter downward. 2. the matter expands and decreases in density. 3. an up-and-down flow of matter produces a convection current. 4. matter is heated. 5. warmed matter is forced upward. question 2 options: a) 4, 2, 5, 1, 3 b) 2, 4, 3, 1, 5 c) 3, 2, 5, 4, 1 d) 1, 4, 2, 5, 3