A drug company is testing the effectiveness of a new blood pressure medicine using rats as test subjects what are some possible factors that must remain constant during the testing?

In the 1800s, one of the statements in john dalton's atomic theory was that atoms are indivisible. later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. what happened to the indivisible atom part of dalton's atomic theory, and why?

How does the presence of oxygen affect the chemical pathways used to extract energy from glucose?

What are several ways to reduce the effect of friction