Final answer:
The first person to investigate the relationship between the pressure of a gas and its volume was E) Robert Boyle.
Step-by-step explanation:
The first person to investigate the relationship between the pressure of a gas and its volume was Robert Boyle.
Boyle, an Irish chemist, conducted experiments using a J-shaped tube partially filled with mercury.
By varying the pressure on a gas sample and measuring its resulting volume, Boyle discovered that the volume of a given amount of gas held at constant temperature is inversely proportional to the pressure under which it is measured. This relationship is known as Boyle's Law.