Question

1. match the correct term to complete the sentence.

a(n) variable does not change in an experiment.

1. choose the best answer.

a student is conducting a combustion experiment with fire and without help from anyone. which rule is violated?
working alone in the lab
leaving an experiment unattended
being serious in the lab
eating and drinking in the lab

Explanation:

For question 20: In an experiment, a variable that does not change is called a constant variable.
For question 21: When a student conducts a combustion experiment with fire alone, they violate the rule of working alone in the lab. Lab safety protocols generally require supervision or a partner, especially for experiments involving fire.

Answer:

1. constant
2. working alone in the lab