Density Concept
This property of matter measures the compactness of the particles. It is a ratio of mass/volume.
What is density?
This is the formula for calculating density.
What is . . .
d = m/v
density = mass/volume
If you could see the particles inside a low density object, this is what the spacing would look like.
Check each other. Particles should be spaced out.
This is the definition of volume.
What is the amount of space an object occupies?
This is the largest (longest) animal on Earth.
What is the blue whale?
Substances A and B have the same volume. If substance A has a greater mass than substance B, is substance A's density higher or lower than B's?
Substance A has a higher density.
m = 30 g
v = 10 ml
d = ? (Show proper units!)
d = 3 g/ml
Draw 2 squares that show equal volume, but different masses. Circle the one with the greater density.
Check each other. Look for a circle around the box with more particles inside.
This is what you should do to an electronic balance before finding the mass of a chemical if you don't want the display to include the mass of the container.
What is zero the scale or push the zero button?
This is the only type of bird that can fly backward.
What is a hummingbird?
A gold bar is cut into three pieces. When the gold is cut, what happens to the density of the smaller pieces? (Increases, decreases, or stays the same)
The density will stay the same. (There will be less volume, but there will also be less mass in each bar.)
A silver bar has a mass of 68 g and a volume of 6.48 cm3. This is the density of silver.
What is . . .
10.49 g/cm3
Draw 2 squares that have different volumes. Illustrate the same amount of mass inside both of them. Circle the object with the greater density.
Check each other. The smaller box should be circled. The number of "particles" inside both boxes should be the same.
This measurement is equal to 1 ml.
What is 1 cm3
This is the chemical formula for ozone.
What is O3?
A balloon is filled with neon gas and released into the air. Neon has a density of 0.84 g/L. Air has a density of 1.2 g/L. Describe what will happen to the balloon when it is released.
The balloon will rise because it is less dense than the air.
A student finds a shiny piece of metal that she thinks is aluminum. She determines that the metal has a volume of 25 cm3 and a mass of 282.5 g. Use the density chart to determine the identity of this metal.
No, it is lead. Its density is 11.3 g/cm3
Oil is less dense than water.
Corn syrup is more dense than water.
Draw a density column for these substances.
Check each other. Oil on top, water in middle, corn syrup on bottom.
In a lab, you determine the densities of several materials. You then obtain a liquid with an unknown density and observe which of the materials sink and float in it.
This is how you would use your data to determine the density of an unknown substance.
What is . . .
You would know the density of the unknown liquid is LESS than the density of the objects that SANK in it, but GREATER than the density of the objects that FLOATED in it. You could use the numbers to estimate a value for the unknown.
This planet has the most moons in our solar system.
What is Jupiter? (It has at least 79 known moons.)
What would happen to the density of a person if she traveled to the moon?
Her density would remain the same because her mass and volume would be the same as when she is on Earth. (Note: Gravity on the moon is different than earth, so her weight would change due to a different force pulling on her.)
A flask that can hold 158 g of water (with a density of 1 g/ml) can only hold 127 g of ethanol at the same temperature. What is the density of ethanol?
d = 0.8 g/ml
Draw a substance with a density of 10 dots per 1 box.
Then, draw the box cut in half. Illustrate the number of dots that should go in each half-box.
Which of the following changed when you cut the box: mass, volume, density
Check each other. Each half-box should have 5 dots.
The mass and volume changed.
The density remained the same.
Challenge: A 34.5 g gold nugget is dropped into a graduated cylinder containing water. The density of gold is 19.3 g/cm3. If the water in the cylinder began at 50 ml, what marking will the water level rise to when the nugget is completely covered?
51.78 ml . (About 52 ml)
This is the official English term for a group of porcupines.
What is a prickle?