Today we will learn three important scientific principles:
- All matter in our world can be categorized as solid, liquid or gas.
- Different liquids can have different densities.
- The molecules are more compact in some substances than others.
In our first experiment, pour equal amounts of oil, water and syrup into a large glass.
Guess what will happen?
Will the liquids all mix or will they separate?
In the end, the syrup, the most dense liquid, sunk to the bottom. Water sat in the middle, and oil rose to the top.
For fun, we decided to drop some solids into our solution. After making hypotheses, we found the penny to lie on the bottom of all the liquids, a lego brick to sit on top of the water, and a wood chip to float on top of the oil.
Is the penny the most dense?
Is the lego heavier than the oil but not as dense as the syrup?
Are all the liquids more dense than the wood chip?
To learn more about solids, liquids and their densities, we can experiment with an egg in a large glass of fresh water. As we slowly add salt to the water, the egg will begin to rise to the top!
Why did it happen?
Salt dissolved in water increases the density of water. Denser liquids are better at keeping objects afloat.
This is why many things that sink in fresh water will float in salt water.
