Good work. You can go ahead and do #3 for your actual experiment.
Preliminary Questions:
1. Watch the 'red' particle for a couple of minutes, estimating the average time between its collisions and its average speed (one of the speeds given near the top of the screen corresponds to that of the 'red' particle--which is it?). It looks like the average speed is around 5. The average time is 3 seconds. I believe the 1st number on the screen that fluctuates more represents the red particle.
2. Watch the 'blue' particle, and speculate on what property of this particle is different from that of the other particles. It differs in speed, it seems to be moving at a slower rate. It is not so scattered.
3. Watch as the 'red' particle sometimes turns yellow. What causes this? What property does the particle have when it is yellow? It never changed to yellow. However, it looked like some of the green molecules changed to yellow and that may be because they interacted with the red molecule.
4. What might the graphs represented at the right of the screen represent? The graphs may represent speed vs. time.
Those graphs represent frequency vs. speed--how often each of the speed ranges is observed.