Students will conduct a laboratory experiment using the following materials: a Bunsen burner, a beaker of water, glass tubing, four test tubes containing different chemicals, and rubber stoppers. Which of these steps is most critical for students to follow when using these materials in the lab?
A
wearing eye protection at all times
B
writing the lab procedure in a notebook
C
washing hands before starting the experiment
D
placing a stopper on all test tubes before heating them
