2.2 B Notes Density

Main Idea: Matter that is lower in density is “lighter” in comparison w/ another matter of the same volume. Visa Versa: higher density = “heavier” matter.

What is meant by the density of matter?

DENSITY Describe: Density is a comparison of how much matter there is in a certain amount of space.

Which one is more dense? A B

Now which one is more dense? A B

In science, what is the “basic matter” that we use to compare the densities of all other matter to? And what is the density of this “basic matter”?

WATER IS THE BASIC MATTER! DENSITY = 1g/cm 3 or 1g/ml

Describe Liquid Layers If you put together liquids that don’t mix & have different densities, they will form layers, like salad dressing! High density liquids go to the bottom. Low density stay on the top.

Liquid Layers – Which liquid has the highest density? Which liquid has the lowest density? Which liquid has the middle density?

ANSWER– Lowest Middle Hhighest

Imagine that the liquids have the following densities:  10g/cm 3.3g/cm 3.  6g/cm 3.5g/cm 3. Which number would go with which layer?

10g/cm 3 6g/cm 3 5g/cm 3 3g/cm 3 ANSWER

Calculating Density Equation: density = mass OR d = m/v volume Units : g OR g Since 1cm 3 is equal to cm 3 ml 1ml of volume! WRITE THESE DOWN ALSO! m = d x v v = m/d

Practice Density Problems: 1. Frank has an eraser. It has a mass of 3g, and a volume of 1cm 3. What is its density?

1. Frank’s Eraser ANSWER. It has a mass of 3g, and a volume of 1cm 3. What is its density? d=? m = 3g v = 1cm 3 d = 3g / 1cm 3 = 3 g/cm 3

2. Jill has a gel pen. The gel pen has a mass of.28g and a volume of 1.2ml. What is the density of the pen?

2. Jill’s gel pen ANSWER. The gel pen has a mass of 0.28g and a volume of 1.2ml. What is the density of the pen? d= ? m = 0.28g v = 1.2ml d = 0.28g / 1.2ml = g/ml

3. Find the mass of lead if the volume is ml, and the density is 11g/cm 3.

3. Mass of lead ANSWER: if the volume is ml, and the density is 11g/cm 3. d=11g/cm 3 m = ? v = 0.750ml m = d x v = 11g/cm 3 x 0.750ml = 8.25 g

4. Find the volume of a material that has a density of 0.1 g/ml and a mass of 5.5g..

4. Material volume ANSWER: that has a density of 0.1 g/ml and a mass of 5.5g. d=0.1g/ml m = 5.5g v = ? v = m/d = 5.5g / 0.1g/ml = 55ml.

Reviewing Your Notes is a Great Idea! What is the formula for density? What happens if you pour together liquids that have different densities? Will the liquid on the top have the highest or lowest density? Will the liquid on the bottom have the highest or lowest density?

Super Scientist Question of the Day Jake has a book, a ruler, and a balance. How can Jake find the density of the book with the tools he has?