BURN SUGAR (ring-stand) OR MELT CHOCOLATE Ask students why they
smell what they do?
Slide 3
Kinetic Theory of Matter All matter is made up of atoms and
molecules that act like tiny particles. These tiny particles are
always in motion. 3
Slide 4
Measurements indicate that the average speed of oxygen
molecules in 20C air is an amazing 1700km/h. At this speed, the
odor from a hot cheese pizza in Washington, D.C., should reach
Mexico city in about 115 minutes. Why dont we smell food from
Mexico?
Slide 5
Bulb ThermometerTemperature How hot or cold something is
(Colloquial definition) The average speed (kinetic energy) of the
particles in a substance. (Scientific) Speed = Temperature Speed =
Temperature 5
Slide 6
What Happens if I add a drop of food coloring to a glass of hot
and cold water? Hot Water Cold Water 6
Slide 7
What Happens if I put a balloon over an Erlenmeyer Flask and
put it on a hot plate/burner? Why? Erlenmeyer Flask Balloon 7
Slide 8
Density Density is the amount of matter contained in an object
in a given volume. Density = mass of object / volume of object
Mass: grams Volume: cm 3 Density: g/cm 3
Slide 9
Mass
Slide 10
Volume if regularly shaped
Slide 11
Volume irregularly shaped Water Displacement
Slide 12
A Graduated Cylinder Measures Volume
Slide 13
Which one has a higher density? The brick and the sponge have a
similar volume meaning they take up roughly the same amount of
space but the brick will be much heavier than the sponge. Since the
brick has more mass it has a higher density.
Slide 14
Density of Common Objects Water = 1g/cm 3 Gold = 19.3g/cm 3
Concrete = 2.7g/cm 3 Iron = 7.8g/cm 3 Ice = 0.92g/cm 3 Air
=0.001225 g/cm 3 If an object is denser than water (or another
liquid) it will sink. If an object is less dense than water (or
another liquid) it will float.
Slide 15
Density Column 7 Layer Density Column ObjectDensity g/cm 3
Honey1.42 Light Corn Syrup1.33 Dawn Dish Soap1.06 Water1.00
Vegetable Oil.92 Baby Oil.83 Rubbing Alcohol0.79
Slide 16
Density Formula Manipulation
Slide 17
Density Problems If a 10.0cm 3 block of ice has a mass of
9.17g, what is the density of ice? A piece of tin has a mass of
16.52g and a volume of 2.26cm 3. What is the density of tin? A
piece of metal has a density of 11.3 g/cm 3 and a volume of 6.7 cm
3. What is the mass of this piece of metal? A cube 6cm by 5cm by
3cm has a mass of 450g. Calculate its density.
Slide 18
Handoutsx3 Density Lab Density Column Worksheet Density
problems. Water ml g cm 3 experiment
Slide 19
Salt Water vs Fresh Water Egg Demo: Which one is denser? Which
one is it easier to swim in?
Slide 20
Density Question If I have a wooden block that has a mass of
20g and a volume of 26cm 3. What is its density? What happens to
the density of that block of wood if you cut it in half? 20
Slide 21
WOOD BLOCK WOOD BLOCK Mass = 20g Volume 26cm 3 Density =
0.77g/cm 3 WOOD BLOCK TWO WOOD BLOCKS WOOD BLOCK Mass = 10g Volume
13cm 3 Mass = 10g Volume 13cm 3 Cut in half Density = 0.77g/cm 3
What Happens if I cut one of the small wooden blocks in half again?
WOOD BLOCK WOOD BLOCK Mass = ??? Volume = ??? Density = ??? 21
Slide 22
Density does NOT depend on the amount of the substance you
have. Regardless of whether you have a small piece of gold or a
giant truck full of it, the density of gold will be 19.3g/cm 3
Slide 23
Volume Displacement It is important to remember that for h 2 0
1g = 1ml = 1cm 3 1000kg = 1000L = 1m 3 H 2 0 = 1g/cm 3 or 1000kg/m
3
Slide 24
How much of an Object will Float above Water?
Slide 25
Iceberg!!!! What percentage of an iceberg is hidden beneath the
water? Density of water is 1g/cm 3 Density of Ice is 0.92g/cm 3 So
0.92 g/cm 3 / 1 g/cm 3 = 0.92 x100 = 92%
Slide 26
Just the Tip of the Iceberg!!!
Slide 27
Slide 28
Knock on Wood A branch from a tree extending out over a river
snaps and falls into the water. If it has an overall density of
0.7g/cm 3, will it sink or float and if it floats how much of it
will be visible?
Slide 29
Knock on Wood A branch from a tree extending out over a river
snaps and falls into the water. If it has an overall density of
0.7g/cm 3, will it sink or float and if it floats how much of it
will be visible?
Slide 30
Floating Basketball A basketball has a mass = 624g and a volume
of 7512.1cm 3. What percentage of a basketball will float above
water?
Slide 31
Floating Basketball A basketball has a mass = 624g and a volume
of 7512.1cm 3. What percentage of a basketball will float above
water?
Slide 32
D = m/v = 624g/ 7512.1cm 3 = 0.831g/cm 3 D ball / D water =
0.831g/cm 3 / 1g/cm 3 x 100 = 8.3% 91.7% of a basketball will float
above water.
Slide 33
Rank each Objects Density from the Most Dense to the Least
Dense
