1. Do Now Convert the following to scientific notation:
16,000
.00123
Convert the following back to normal notation:
2.3 x 104
3.6 x 10-3
Find % error:
A student measures the density of a metal to be .4 g/cm3. Her teacher tells her the density is .6 g/cm3
1.6 x 104
1.23 x 10-3
23,000
0.0036
D (%) = Diff from accepted value
x 100
Accepted Value
D (%) = .2 g/cm3
x 100
.6 g/cm3
D (%) = 33%
D (%) = .6 g/cm g/cm3
x 100
.6 g/cm3
D (%) = % x 100

2. Density Review

3. Density is a measure of “mass per unit volume” or “how tightly packed” a material is.
The formula is Density = Mass
Volume
measured in grams per cubic centimeter:
g/cm3

4. Volume Units? Amount of space something takes up
Rectangle or cube= length X width X height
Example: L = 5 W= 2 H = 3
Volume? 30
cm3
Units?

5. Irregular solid: (anything you can’t measure L X W X H):
Here are the steps to figure it out:
Read the volume before
Drop sample in water
Read the volume after
Subtract

6. Factors that Affect density
Does the size of an object affect density?
How does temperature affect density?
How does the phase of matter affect density?
No matter how much you have, if it’s the same material, same density
When things are heated, they expand= less dense
Least dense
Most dense

7. As an object expands, density decreases
(as size increases)
As temperature increases, density decreases (water is the exception)
As you go from solid to liquid to gas, density decreases (except water)

8. Density Problems D=M divided by V, M=D times V, V=M divided by D
Density=mass
volume
Cover the variable you need- what’s left is your formula
D=M divided by V, M=D times V, V=M divided by D M D V

9. Try These!
1. D= 3. D=4 g/cm3 5. D= 10 g/cm3 M= 7 g M= 12 g M= 40 g V= 14 cm3 V= V= 2. D= 8 g/cm3 4. D= 6. D=5 g/cm3 M= M= 32 g M= V= 2 cm3 V= 8 cm3 V=5 cm3
.5 g/cm3
3 cm3
4 cm3
4 g/cm3
16 g
25 g