1. Stupid is as stupid does sir…
Density
Stupid is as stupid does sir…
No! It’s not about how smart you are…

2. Density is: = 1 atom or molecule Density describes how close together
the molecules of a substance are…
Here are two examples of substances
with different density
You should be able to see that ratio
of the mass (amount of matter) vs.
volume (space it takes up) is different

3. Measuring Density: mass Density = volume
To measure Density, you need to know
how much matter (mass) is packed
Into a certain space (volume)
So the formula for Density is:
mass
Density =
volume
A fun way to remember this:
We call it the Equation of LOVE!

4. Comparing Density: = 1 atom or molecule If the density of this
substance was 1 g/cm3
The density of this
substance would be?
The density of this
substance would be?
HIGHER!!! Molecules
are closer together!!!
LOWER!!! Molecules
are farther apart!!!

5. Notice how close together the molecules/ atoms are!
Very Dense:
= 1 atom or molecule
Notice how close together the molecules/ atoms are!
When they are this close, the density will be pretty high.

6. Notice that the molecules/ atoms are a little farther apart.
Less Dense:
= 1 atom or molecule
Notice, that the volume is pretty much the same as the previous sample!
Notice that the molecules/
atoms are a little farther apart.

7. Notice how far apart the molecules/ atoms are!
Even Lower Density:
= 1 atom or molecule
Notice, that the volume is pretty much the same as the previous two samples!
Notice how far apart the molecules/ atoms are!
When they are this close, the density will be pretty low.

8. Result of Density:
Substances with a higher density will sink
below substances with a lower density
Think of it a little like falling into a net. If the cords are
really far apart, you could fall through (“sink”). If the
cords are really close together, you will sit on top (“float”)!
Substances with a lower density will float
above substances with a higher density

9. Density of the Phases: Think: Is there any way the density
of an object can change?
= 1 atom or molecule
The density of liquids are
Typically less than a solid,
but more than a gas
The density of solids are
typically more than either,
liquids or gases
The density of gases are
typically less than a solid;
but also less than a liquid

10. Variables to Density
Temperature
Mixture