Susan Solomon's research has helped determine the cause of the ozone hole.
If you've ever been in a room where a piping hot pizza was delivered, you've been made aware of the fact that it can quickly spread throughout a room, as evidenced by the pleasant smell that soon reaches your nose.
The gasses travel at great speeds, but they collide with each other and travel in many different directions before reaching their destination.
Billions of particles will be created per second at room temperature.
A net movement of species from high to low concentration areas takes place when the gaseous atoms or molecule move randomly.
After the stopcock is opened, more H2 molecule move to the O2 side than O2 molecule move to the H2 side.
The concentration gradient, the amount of surface area available for diffusion, and the distance the gas particles must travel are some of the factors that affect the rate.
The rate of diffusion equation shows that the time required for diffusion is proportional to the rate.
Gas molecule dispersal occurs in a container.
When a gas passes through an opening that is smaller than the mean free path of the particles, it causes efffusion.
Only one particle can pass through at a time.
If a mixture of gases is placed in a container with porous walls, the gases effuse through the small openings in the walls.
The lighter gases pass through the small openings at a higher rate than the heavier ones.
A balloon filled with air is full.
A balloon filled with helium is partially deflated because the smaller, light helium atoms are easier to see in the rubber than in the air.
Hydrogen effuses four times faster than oxygen.
Nitrogen gas effuses at a rate of 79 mL/s at certain pressures and temperatures.
This is an example of how determining times and rates differ.
It takes 243 s to get through a tiny hole.
To remember how rate relates to time as well as how it relates to mass is important to resist the temptation to use the times directly.
Since Ne is lighter than Xe, the time of effusion for Ne will be smaller than for Xe.
A party balloon is inflated to 23 of its original volume in eight hours.
This is the final example showing how to calculate the mass from the data.
An unknown gas effuses 1.66 times faster than CO2.
The only gas with this mass is CH4.
Hydrogen gas effuses through a porous container at a faster rate than an unknown gas.
Estimate the mass of the gas.
Nuclear power plants and weapons can be enriched with gaseous diffusion.
The kind of uranium that is "fissile" is 0.72% of 235U.
Nuclear bombs need even higher concentrations of fuel.
Graham's law can be used to enrich uranium to desired levels.
In a gaseous enrichment plant, the only compound that is volatile enough to work is slowly pumped through large cylindrical vessels.
The other side of the barrier is not being evacuated.
The heavier 238UF6 molecule diffuses through the barrier a little faster than the lighter 235UF6 molecule.
The residual gas is slightly deplete and the gas that has passed through the barrier is slightly enriched.
There is a small difference between the weights of 235UF6 and 238UF6 in one diffuser.
The desired level of enrichment can be achieved by connecting many diffusers in a sequence of stages.