The relationship between an element's isotope and an element's atomic mass are related by...?

•what conclusions can you make about the relationship between the volume of a gas and its temperature? • what conclusions can you make about the relationship between the volume of a gas and its pressure? • what possible variables have you not accounted for? as you did the procedures, is it possible that the atmospheric pressure may have changed? if it did change over the course of your experiment, then how would your results have been affected?