Key vocabulary: Density, mass, volume

What is density? Density is a measure of how compact the particles in a substance are. Examples: A softball is less dense than a bocce ball. A balloon filled with water is more dense than a balloon filled with air.

Particles in a Square Which square is more dense? left right

Now which one is more dense?

Density depends on 2 things: Mass - how much Matter is in an object - measured in grams with symbol g or kilograms with symbol kg Volume - how much space the object takes up - measured in milliliters (mL) or Liters (L) or cubic centimeters cm3 or cc

Which is more dense? Clothes spread out all over your bedroom OR The same clothes packed in your suitcase? Why? All your books and notebooks jammed in your back pack OR One book by itself in your back pack Why?

Density can be calculated! Density = D = mass/Volume Formulas are written with symbols So, the formula for density is: D = m/V Units for density: kg/L g/cm3 g/mL Why are these the units for density? Any mass unit over any volume unit can be a density unit.

Let’s try a density problem together Frank has a paper clip. It has a mass of 9g and a volume of 3cm3. What is its density? Frank also has an eraser. It has a mass of 3g, and a volume of 1cm3. What is its density?

Work on these problems with your neighbor. Jack has a rock. The rock has a mass of 6g and a volume of 3cm3. What is the density of the rock? Jill has a pen. The pen has a mass of 8g and a volume of 2cm3. What is the density of the pen?

Now, try these on your own. Alicia has a watch. It has a mass of 4g and a volume of 2cm3. What is the density of the watch? Mia has a wallet. It has a mass of 15g and a volume of 5cm3. What is the density of the wallet?

Find the density of a wood block: 1. Measure its mass _____ g 2. Determine its volume. length x width x height = volume ___cm x ___cm x ___cm = ________ 3. Calculate its density. formula: NPI: Answer with units:

Liquid Density Review! What is the formula for Density? How do we derive the density of a liquid, without getting the balance all wet?

How to derive the density of a liquid? 1. Measure the mass of an EMPTY graduated cylinder and record. 2. Place some liquid in the graduated cylinder (carefully without making a mess!) 3. Mass the graduated cylinder WITH the liquid and record.

Continued… 4. Subtract! 5. Read the graduated cylinder to measure the VOLUME of the liquid: 6. Calculate the DENSITY using formula.

Let’s find the density of some liquids! Pancake syrup Vegetable oil Mineral oil Motor oil Glycerine Dish soap Isopropyl alcohol Deionized water Salt water Be sure to put on lab aprons before beginning your experiment!

Density of ____________________ Data Table Mass of EMPTY graduated cylinder: Mass of graduated cylinder & liquid: - Mass of liquid: Volume of liquid: Density of liquid:

Liquid Layers If you pour together liquids that don’t mix and have different densities, they will form liquid layers. The liquid with the lowest density will be on the top. The liquid with the highest density will be on the bottom.

Liquid Layers Check out this picture. Which layer has the highest density? Which layer has the lowest density? Do solids have greater density than liquids? Predict: How will various solids settle out in the liquid layers?

Liquid Layers – Try with your neighbor Which liquid has the highest density? Which liquid has the lowest density? Which liquid has the middle density?

Liquid Layers – Try on your own! Imagine that the liquids on the right have the following densities: 15g/cm3 10g/cm3 3g/cm3 9g/cm3 7g/cm3 12g/cm3 Match the colors to the correct densities.

Review What is the formula for density? What happens if you pour together liquids that have different densities? Do solids have greater density than liquids? Will the substance on the top have the highest or lowest density? Will the substance on the bottom have the highest or lowest density?

Super Scientist Question of the Day Jake has an irregularly shaped rock, a ruler, graduated cylinder, water and a balance. How can Jake find the density of the rock with the tools he has?