Liquid Column

Why did some objects sink while some objects floated? Also, why did some objects float in the middle of the columg? Do you think the "mixed" one will separate by Monday?

I believe that the reason why some objects floated because the object is lighter than the liquid. Same idea, some objects sank because the object is heavier than the liquid.

Then what causes “heavier” and “lighter”? It’s all about density. The objects that are more dense than the liquid will sink, and the objects that are less dense than the liquid will float.
So now we can clearly see the red liquid are more dense than yellow one, the yellow one are more dense than the clear one and so on. Therefore, if an object float between red and yellow, the density of that object must be lighter than the red liquid but heavier than the yellow liquid.

I think the mixed one will separate by Monday. Although it mixed but it still has 4 different materials in it.