Preview - Atomic Forces And Phase Transitions

Going Further Option 2 -Two Types of Atoms (More chemistry less coding)

Now that you've seen the basic model with one type of atom, it's time to explore something a little more advanced. The model below basically behaves the same way, but there are two types of atoms. You don't have to answer the questions in order, or even answer them at all if you don't want to.

 

Questions

Please answer the questions below.

There are now three different EPS parameters. EPS-AA is the epsilon value for the potential function between two A type atoms. EPS-BB is the epsilon value for the potential function between two B type atoms. EPS-AB is the epsilon value for the potential function between an A and B type atoms.

Play around with different values and see what types of behavior you get. Write down what you find and try explain why you see what you do. 

 

Solutions are homogeneous mixtures of two or more pure substances. In a solution, the solute is dispersed uniformly throughout the solvent.

What values of EPS-AA, EPS-BB and EPS-AB result in a solution forming? If a solution doesn't form, what is forming? 

You can raise and lower the temperature to get the atoms to move around more and then settle back down. This can help reach an equilibrium faster. 

Is the are the melting and boiling temperatures different depending on the values of EPS-AA, EPS-BB and EPS-AB? Does this relate to whether they form solutions at those values?

In the real world, what types of inter-molecular forces could be responsible for EPS-AA, EPS-BB and EPS-AB being different relative strengths?

If EPS-AA, EPS-BB and EPS-AB are all equal, then the atoms should mix randomly. Is uniform mixing the same as random mixing?

Note: if you haven't done the other extra credit section yet, do that before doing the next two questions.

Try having the atoms scale their color based on their energy. Does this help you explain to yourself or others why you see the different behaviors you do with different values of EPS-AA, EPS-BB and EPS-AB?

Add two sliders for the diameters of A and B atoms and change the code accordingly. Play around with making the atoms different sizes in addition to changing the values of EPS. What kind of behaviors do you get? Does this change the packing structure when the atoms are in a solid?

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.