The density is the ratio of mass (stuff that
makes up an object) and its volume (the
amount of space that stuff takes up). The
more mass an object has in a give amount of
space, the more dense it is. To say it another
way, the more con”densed” the matter is, the
more dense it is!
Density can be calculated using the following formula:
Whereas, D =
M =
V =D = MV
mass
volume
density
M
D V
Example: A wooden block with a mass of 80.0 g is 8 cm long, 3 cm wide, and 4 cm high. Calculate the wooden block’s density.
Length =
Width =
Height =
8.0 cm
3.0 cm
4.0 cm
8.0 cm
3.0 cm
4.0 cm
Volume = L x W x H
Volume = 8.0 cm x 3.0 cm x 4.0 cm = 96.0 cm3
Step 2
Wait for all of the water to flow out of the overflow can into the beaker positioned below the spout.
Step 3
Take the water in the beaker and pour it into the graduated cylinder. Be sure not to spill any!
Step 4
Read the volume of the water in the graduated cylinder. This should equal the volume of the mineral originally placed in the overflow can.
Determining the volume of an irregular objectStep 1
Place the object in the overflow can.
Overflow Can
Does changing the size of a pure substance change its density?
Density = 16 s per 8 sDensity = 2 s per
Does changing the size of a pure substance change its density?
Density = 8 s per 4 sDensity = 2 s per
Does changing the size of a pure substance change its density?
Density = 4 s per 2 sDensity = 2 s per
What happens to the density of a material when you break it into pieces?
D = m/v
M = 2,000 g
V = 1,000 mL
D = ? g/mL
Answer: The density does not change !!!
M = 24 g
V = 12 mL
D = ___ g/mL
M = 14 g
V = 7 mL
D = ___ g/mL
M = 10 g
V = 5 mL
D = ___ g/mL
What happens to the density, volume and mass of most materials when you heat them?
D = m/v
M = 10 g
V = 1 mL
D = ____ g/mL
D = m/v
M = 10 g
V = 1 mL
D = ____ g/mL
D = m/v
M = 10 g
V = 1 mL
D = ____ g/mL
D = m/v
M = 10 g
V = 5 mL
D = ____ g/mL
→ No change
→ Increases
→ Decreases
Finding the Percentage BELOW the Surface
Step 1
Divide the density of the object by the density of the fluid it is floating in.
Ex. Ice = 0.92 g/mL
Water = 1.0 g/mlStep 2
Multiply your answer from Step 1 by 100. This equals the percent found BELOW the surface.
Ex. 0.92 x 100 = 92% This means 92 percent of an ice cube is found below the surface of water.
8.0 % Above
92.0 % Below
If the density of ice is 92% of the density of water, than 92% is found BELOW the surface. How much is found above?
Water
Ice