Question

a group of students trap gas in an expandable container and measures 3 variables using sensors. they record the results as variables a, b, and c below.
which of the following variables is a control variable?
variable a
variable b
variable c
variables b and c

Explanation:

A control variable is a variable that is kept constant throughout an experiment. In the given data, Variable A has a constant value of 1.0 in all the recorded results. Variable B changes (2.0, 4.0, 6.0, 8.0, 10.0) and Variable C also changes (20.0, 10.0, 6.7, 5.0, 4.0). So, Variable A is the control variable.

Answer:

C. Variable A