Density

The Density of a substance is determined by its Mass (weight) compared to its Volume (space occupied). Some facts: -If two things have the same weight (mass), then the one that takes up less space is the denser of the two Density doesn’t just involve solids; Gases and liquids also have specific densities based on how and what they are made out of. Which weighs more? A gallon of water or A gallon or paint?

We can find out the density of anything as long as we know its ____________ and ____________. Mass Volume ……...Then we divide the mass by the volume. The resulting number will be the density. Remember: D = M / V The density of water is 1 Sometimes we can find out about density by putting different substances together: What happens when we mix oil and water??

Denser materials always try to sink and less dense materials Why? Even though we may not know the density of oil, we know that is less than water. Denser materials always try to sink and less dense materials always try to rise. This is not just true for liquids!

Sometimes the density of substances can be changed How? Applied Pressure or a change in temperature Examples:

What Weighs More: Styrofoam Steel or This is truly a meaningless question because we aren’t told the amount! We are temped to say that steel is heavier, but this is because we are really thinking about density, rather than weight.

Density is a far more important property to consider when dealing with anything in the physical world…. It is also important to understand that there are a wide variety of densities in our universe. Take a look at a few…. 0.0000000000000000000000002 Space Air .001225

Water Gasoline Copper Gold The U.S.S. Ronald Reagan 1 0.7 8.92 19.32 <1

Neutron Star (Pulsar) Earth Saturn Coke Diet Coke 5.5 .7 1.08 .97 7,00000000000000000000 5.5 Saturn .7 Coke 1.08 Diet Coke .97