Diffusion and Effusion: Evidence of Moving Particles

• Gases diffuse to any available space around them.
• Gases do not diffuse at the same speed.
• In 1823, the Scottish chemist Thomas Graham reported that the ___ ___ of a gas is ___ proportional to the ___ of its ___.

  replacement value ; inversely ; square root ; density
• "In 1823, the Scottish chemist Thomas Graham reported that the replacement value of a gas is inversely proportional to the square root of its density." This statement is known as ___.

  Graham's law of diffusion
• Graham's law is a result of his findings that the rate of ___ is ___ proportional to the ___ of gas that diffused in a given time.

  diffusion ; directly ; volume
• The density of a gas is proportional to its molar mass.
• ___ is the escape of gas molecules from a compartment under pressure through a tiny hole, such as a pinhole in a balloon, into a vacuum.

  Effusion
• In 1848, Graham published another one of his findings, which states that under the same temperature and pressure, lighter gases effuse ___ than gases with higher molecular masses.

  faster