Density (Amore' Thompson)

Title: Layer Density Tower

Principle(s) Investigated: What is density? Why do some objects float or sink relative to other objects?

Standards:

MS-PS1-1. Develop models to describe the atomic composition of simple molecules and extended structures.

Developing and Using Models

Modeling in 6–8 builds on K–5 and progresses to developing, using and revising models

to describe, test, and predict more abstract phenomena and design systems.

Develop a model to predict and/or describe phenomena. (MS-PS1-1),(MS-PS1-4)
Develop a model to describe unobservable mechanisms. (MS-PS1-5)

Analyzing and Interpreting Data

Analyzing data in 6–8 builds on K–5 and progresses to extending quantitative analysis to investigations, distinguishing between correlation and causation, and basic statistical

Materials:

- Glass Vase

- Water

- Dish Soap

- Honey

- Vegetable Oil

- Maple Syrup

- Rubbing Alcohol

Procedure:

1. Pour equal amounts of solution to prepare for density tower. Add food coloring to liquids that are clear, so you can see them clearly in the tower.

2. Carefully pour equal amounts of the liquids from most dense to less dense in glass vase. Try to not have liquids touch the side of the vase because once the liquid touches the other liquids density will take its place in order to level on top of the previous liquid.

3. Do not squirt the liquids out into the glass vase because it will mess up the density tower. You want to spread the area of layering because you do not want to cause too much turbulence that is going to disturb the building of the layers.

2. Optional: To add objects to the density tower to see where it will fall while in the density tower of liquids.

Student prior knowledge: definition of mass, units for mass, basic math skills such as multiply and divide, possible experience cooking

Explanation: Density is basically how much “stuff” is packed into a particular volume. It’s a comparison between an object’s mass and its volume. The equation: density = mass ÷ volume. Lighter liquids (like water or vegetable oil) are less dense than heavier liquids (like honey or corn syrup) so they float on top of the heavier liquids. The same amount of two different liquids you used in the container will have different densities because they have different masses. The liquids that weigh more (a higher density) will sink below the liquids that weigh less (a lower density).

(Density Video on Email)

LAVA LAMP

1. Pour 1/8 worth of water in container or cup.

2. Place 3-5 drops of food dye.

3. Fill the rest with vegetable oil.

4. Drop Alkas-elter Tablet in water

5. Enjoy Lava Lamp

Questions & Answers:

1. How can you tell how dense something is?

A: The equation for density is mass over volume. Once you have the volume by using basic math equations to determine the space that is being taken up then you are able to place this is the overall equation of density. The mass is also a requirement, so if it can be placed on a scale then it will give a more accurate answer on its density.

2. Can you have a density less than 1?

A: Of course you can! There are a lot of liquids that are less than 1. The density of water is 1.00 g/cm^3 and a lot of oils are less than the density of water.

3. How do you write density?

A: Density is measured by mass over volume. The units for density is grams over cm^3. As we know mass is weighed and the units of mass is grams. When we look at the volume we use centimeters as our units and when you calculate volume it is always cubed.

Applications to Everyday Life:

1. Cooking - frying food, salad dressing (Italian)