Asample of oxygen gas is sealed in container x. a sample of hydrogen gas is sealed in container z. both samples have the same volume, temperature,
and pressure. which statement is true?
(1) container x contains more gas molecules than container z.
(2) container x contains fewer gas molecules than container z.
(3) containers x and z both contain the same number of gas molecules.
(4) containers x and z both contain the same mass of gas.