What makes up matter? We can’t see it directly, but observing some details might help us imagine what’s going on at a deeper level.

I have two glass bottles of water that I drop red dye into. All the water came out of my faucet, but the two bottles behave differently. What do you notice? What do you think might be happening? How do you picture or model the water and dye interacting? How could you investigate this on your own? What would you try?