1. Density Density describes how heavy an object is compared to its size.
Think of two cubes that are the same size. One is made of metal and the other is made of Styrofoam. Which will be heavier?
All substances have different densities, therefore, you can identify a substance if you know its density

2. Mass Mass is the amount of substance in an object
It is constant no matter where you go, even the moon.
To find mass, we put the object on a balance
Mass is always in grams

3. Volume - two options Volume is how much space an object takes up.
To find the volume of Liquids
Use a graduated cylinder to find the volume
It will be measured in mL
To find the volume of rectangular Solids
Measure length, width, and height; then multiply.
It will be measured in cm3

4. Measuring Solid Volume
10 cm
9 cm
8 cm
We can measure the volume of regular object using the formula length x width x height.
_____ X _____ X _____ = _____
We can measure the volume of an irregular object using water displacement.
Amount of H2O with object = ______ About of H2O without object = ______ Difference = Volume = ______

5. Calculate the volume:

6. Density Units
When we calculate density, the units we use are either g/mL or g/cm3. How do we know which set of units to use?
g/ml - liquids
volume of liquids are measured in milliliters
g/cm3 for solids
Volume of solids are measured in cm3

7. Water What is the density of water?
If an object is less dense than water it will float.
If an object has a greater density than water it will sink.

8. To Calculate Density The formula to calculate something’s density is:
D = density
M = mass
V = volume M D V

9. Practice 1
V = 15 mL
M = 45 g
D = ?
D = m/v 45 g/ 15mL
D = 3g/mL

10. Practice 2
V = 10 mL
M = 100 g
D = ?
D = m/v 100 g/10mL
D = 10 g/mL

11. Practice 3
M = 45 g
D = 9 g/cm3
V = ?
V = m/d 45 g/ 9 g/ cm3
V = 5 cm3

12. Practice 4
M = 144 g
D = 12 g/cm3
V = ?
V= m/d 144 g/12 cm3
V = 12 cm3

13. Practice 5 D = 12 g/mL V = 3 mL M = ? M = d x v 12 g/mL x 3 mL
M = 36 g

14. Practice 6 D = 3.54 g/mL V = 22 mL M = ? M = d x v 3.54 g/mL x 22 mL
M = g