# Density ```1. How can you compare the densities of liquids
without calculations?
2. What is the difference between the mass and
volume of an object?
3. What is density?
4. If you have 30.76 mL how many cubic centimeter
are there?
5. What instrument is used to determine liquid
volume?
6. A rectangular substance has a length of 4.0 cm, a
width of 2.0 cm and a height of 3.0 cm. It has a
mass of 10.5 g. What is the density?
7. What would be the density if the volume of the
substance was 3 ml?
Density
• Mass per unit volume
• Density = mass divided by volume:
D=M/V
• Units are g/mL or
D=
3
g/cm
• Density of water is 1 g/ml
• Objects that are more dense than
water will sink
–Example: 2.78 g/ml
• Objects that are less dense will
float
– Example: 0 .8 g/ml
•Everything has its own density.
•Density is not affected by the size of an object
and can be used to identify what an object is
– Ex.
•Density of copper is 8.9 g/ml
•Density of aluminum is 2.7 g/ml
1. A rectangular solid of unknown density is 5 cm long, 2
cm high and 4 cm wide. The mass of this solid is
300 g, calculate its density.
2. A rock occupies a volume of 20 cm3 and has a mass of
54 grams. Find the density of this rock.
3. A rock has a density of 4 g/ml. and a mass of 16
g. What is the volume this rock occupies?
4 An unknown substance from planet X has a density of
10 g/ml. It occupies a volume of 80 ml. What is the
mass of this unknown substance?
5. What would be the density of 5 g of the substance
from planet X in problem 3?
6. A cube made of an unknown material has a height of
2 cm and a mass of 9 g. Calculate the density of this
cube given this information
Actual Density
Copper
Brass
Steel
Aluminum
Acrylic
Nylon
Pine
PVC
8.9 g/ml
8.0-8.5 g/ml
7.6 g/ml
2.7 g/ml
1.16-1.19 g/ml
1.13 g/ml
.35-.60 g/ml
1.39-1.42 g/ml
```