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

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

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!

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!!!

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.

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.

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.

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

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

Variables to Density Temperature Mixture