A student wants to answer the question “Does adding calcium powder to soil make pea plants grow faster?” She adds calcium powder
to the soil of 12 plants and does not add it to the soil of a second group of 12 plants. She measures the growth of all of the plants in each group for a month. Which statement best summarizes the factors that need to be controlled in this experiment?
We can determine what the dependent and independent variables are in this experiment so that we can narrow down what factors need to be constant.
Dependent variable - Growth of the plants Independent variable(s) - Calcium powder
The control variable are the constant variables in an experiment kept constant to ensure the results of the experiment are valid. Therefore, in this experiment the control variables are...
Control variables - Amount of water, sunlight, type of pea plant, mode of measuring the growth
