9/15/2015
Density
What is density?
 Every object has a measureable features
such as mass and volume.
 Density: The ratio of an objects mass to
volume
Mathematically 
Density of a Solid
 The mass of a solid can be measured using a
balance.
 Mass is a measure of ____________________
______
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Mass Versus Weight
 Mass and weight are not the same thing.
 In chemistry, we measure the mass of an object, NOT
THE WEIGHT.
 Mass is a ______________________ of a material. It
is measured using a balance.
 Weight is a measure of _____________________ and
therefore can change depending on the gravitational pull.
 The ____________________________ that of the
earth so your weight would __________on the moon
but your mass would _____________________.
Density of a Solid (cont)
 The volume of solid can be found 2 ways:
 1) direct measurement – ______________
__________________
o Ex: measure a block
o _____________________
 2) water displacement – irregular shaped
solid
o Ex: volume of a stone
How to Find Volume
 Volume is the ____________
______________________.
 Measuring volume using
graduated cylinders (most
commonly).
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Water Displacement
 Calculating the volume of a solid by
finding the difference of volumes.
 Steps:
 1) Find a starting value
 2) Add the object and read volume
 3) Subtract
 Formula:
Density Standards
 Water is considered to be a standard in terms of density.
 Water has a density of _____________.
 If an object floats in water, the object is
_____________ than water.
 If an object sinks in water, the object is
______________ than water.
Solving for Density
 The formula for density is:
D = m /V
 You can rearrange this using algebra to solve for both mass
and volume!!
m=
V=
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DENSITY TRIANGLE
Example #1:
 A 3.00 mL sample of water has a mass of 2.99 g.
What is the density?
Example #2
 Oil has a density of 0.90 g/mL. If I have a 30 mL
sample of oil, what would be the mass?
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Example #3:
 Aluminum has a density of 2.70 g/mL. If I have a sample of
aluminum that has a mass of 5 g, what is the volume of the
sample.
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