Graham's Law states that the rate of diffusion for a gas is: Independent of the gas's mass. Proportional to the gas's density. Dependent on the temperature alone. Inversely proportional to the square root of the gas's molar mass.

The correct answer is:<br /><br />**Inversely proportional to the square root of the gas's molar mass.**<br /><br />### Explanation:<br />Graham's Law of Diffusion (or Effusion) states that the rate of diffusion or effusion of a gas is inversely proportional to the square root of its molar mass. Mathematically, it can be expressed as:<br /><br />\[<br />\frac{\text{Rate}_1}{\text{Rate}_2} = \sqrt{\frac{M_2}{M_1}}<br />\]<br /><br />Where:<br />- \( \text{Rate}_1 \) and \( \text{Rate}_2 \) are the rates of diffusion or effusion for two gases.<br />- \( M_1 \) and \( M_2 \) are the molar masses of the two gases.<br /><br />This means that lighter gases (with smaller molar masses) diffuse or effuse faster than heavier gases (with larger molar masses).