1. What is Density?

2. What makes a hot air balloon work?

3. Density affects us all in many ways you never thought. Some gases, such as helium and hydrogen, have a density which is less than the density of air, so balloons filled with such gases float and rise in air!

4. It also floats your boat... …and keeps your drink cold.

5. How does Density affect me? One of the most common uses of density is in how different materials interact when mixed together. Wood floats in water because it has a lower density, while an anchor sinks because the metal has a higher density. Helium balloons float because the density of the helium is lower than the density of the air.

6. Density is the concentration of matter in an object. It can be used to identify unknown substances because pure substances always have the same density.

7. Name the 3 Most Dense substances in this list. Copper, Diamond, Wood, Aluminum, Gold, Iron, Lead, Platinum, Air, Water

8. Platinum Gold Lead

9. Name the 3 Least Dense substances in this list. Copper, Diamond, Wood, Aluminum, Gold, Iron, Lead, Platinum, Air, Water

10. Wood, Water and Air

11. Why does the density stay the same regardless of a substance’s size?

12. For example, this steel bridge:

13. And this steel fork have the same density. Why?

14. Because… Density is the concentration of matter in an object. It depends on how much mass is in an object. It also depends on how much space an object takes up. So…

15. If… A substance is big or small, its mass increases proportionally with its volume. In other words, if you make a small copper ball get bigger, you will add mass and volume. You cannot add volume without adding mass just like you cannot subtract volume without subtracting mass. When you lose weight, you get smaller. When you gain weight, you increase in size. So why don’t you go…

16. Take a hot air balloon ride!