18. What is the density of a substance with a mass of 0.90 kg and a volume of 1.2 mL?
21. An oxygen tank in the lab has a pressure of 12 atm at 250C. If the pressure inside the gas tank exceeds 25 atm, the tank will explode. If a fire occurs in the lab, raising the temperature of the gas inside the cylinder to 398oC, will the tank explode?