Is this investigation a controlled experiment or an observational study? Explain your answer.

This drawing shows a human body system. what is the primary function of this body system?

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

As light moves from one material into the next, which of the following affects how much the light waves will refract, or bend? angle at which the ray strikes the medium color of the material density of the material temperature of the light wave