What does a scientist test when using a controlled experiment?(1 point)
1. several variables.
2. a mass of information.
3. a single variable.
4. a conclusion.
3. a single variable.
The correct answer is:
3. a single variable.
In a controlled experiment, a scientist typically tests a single variable. This means that all other factors remain constant or are controlled, while only one factor is deliberately changed or manipulated to observe and measure its effects. By isolating and focusing on one specific variable, scientists can determine its impact on the outcome or results of the experiment.