Topic: Measurement
Aim: Describe density and how it is
measured.
Do Now:
1. Copy the topic, aim and homework
2. Take out the blue Mass Sheet from
yesterday.
3. Tape the Density ISA into ISA section.
HW: Temperature Reading
Let’s review…
1. Describe volume. (Remember the key
word!!!)
2. Describe mass. (Remember the key
word!!!)
3. Identify the instrument used to measure.
4. Identify the instrument used to measure
mass.
5. Identify the units used to measure mass.
Mass = 290.2g
Mass = 536.8gm
Which ball do you think is
more dense? The golf ball
or the ping pong ball? Why?
Density
• Mass per unit volume
Which box has a greater density?
A
B
• Box A has a greater density than Box B
• Why? Because it has a greater mass (more
matter)
• Density of water = 1 g/mL
• Equation = mass = m
volume
v
#1:
What is the density of
a metal block that
has a mass of 525g
and the volume is
50cm3?
Mass: 525g
3
Volume: 50cm
D=m
v
D = 525 g
3
50 cm
3
D = 10.5 g/cm
#2:
The metal block was
split in half. The
mass of each half is
262.5g and the
volume of each half
is 25cm3. Calculate
the density.
Mass: 262.5g
Volume: 25cm3
D=m
v
D = 262.5 g
3
25 cm
3
D = 10.5 g/cm
What is
the block
made of?
Silver =
10. 5
g/cm3
• Density NEVER
CHANGES!!!
M = 20 g V = 10 mL
Density = 20/10 = 2 g/mL
Cut the block in half
M = 10 g
V = 5 mL
Density = 10/5 = 2g/mL
It remains the
same !!!!
• Each pure substance has it’s own
density.
Topic: Measurement
Aim: Describe density and how it is
measured.
Do Now: 1. Take out temperature reading
for me to check.
2. Take out Measuring Volume ditto and
complete 4 – 9.
3. Take out the blue Density Sheet and
complete #3.
HW: Graphing Ditto Side 2
47mL
56mL
35mL
73mL
43mL
7.6mL
#3
The mass of a
marble is 8.8 g.
It has a volume
of 2 mL. What is
the density?
Mass: 8.8g
Volume: 2mL
D=m
v
D = 8.8 g
2 mL
D = 4.4 g
mL
Why will an object float or
sink in water?
More dense
than water
Less dense
than water
Less dense
than water
More
dense
than
water
• FLOATS: object’s density is
LESS than the liquid’s density
• SINKS: object’s density is
GREATER than the liquid’s
density
1.Which liquid
is the MOST
dense?
Support your
answer.
2.Which liquid
is the LEAST
dense?
Support your
answer.
1. Which LIQUID
is LEAST
dense?
2. Which LIQUID
is MOST
dense?
3. Which
OBJECT is
LEAST
dense?
4. Which
OBJECT is
MOST dense?
1. Which LIQUID is
LEAST dense?
• Corn oil
• It’s floating at
the top
2. Which LIQUID is
MOST dense?
• Mercury
• It’s at the
bottom.
3. Which
OBJECT is
LEAST dense?
• Wood
• It’s floating
at the top
4. Which
OBJECT is
MOST dense?
• Copper wire
• It’s at the
bottom.
Why does warm air rise?
Warm air rises bc it is less dense than
cold air which sinks.
Let’s summarize…
1. Identify the equation for determining
density.
2. Describe what do you know about the
density of different substances.
3. Identify the density of water.
4. What would happen to the density of a
substance if it was cut into six pieces?
5. Why do substances float in water?
6. Why do substances sink in water?
The units of density could be
1. milliliters per gram
2. milliliters
3. gram
4. grams per milliliter
What is the density of a
40-gram object with a
volume of 20 milliliters?
1. 2 g
2. 2 ml/g
3. 2 g/ml
4. 2 ml/g
A cube is 1 cm on each side
and has a mass of 2
grams. Will it float?
1. yes
2. no
3. The only way to tell is to put
it in water.
.
The density of water is
1. 1 mL/g.
2. 1 g/L.
3. 1 g/mL.
4. 1 kg/mL.
An object that floats in
water has a density of
1. less than 1 g/mL.
2. equal to 1 g/mL.
3. greater than 1 g/mL.
4. equal to 10 g/mL.
1. Will an object with a
3
density of 3.4gm/cm sink
or float in a cup of water?
Explain why.
2. Will an object with a
3
density of.086gm/cm sink
or float in a cup of water?
Explain why.
Review:
Which piece of laboratory equipment
would be used to obtain the most
accurate measure of the volume of a
glucose solution?
1. triple beam balance
2. graduated cylinder
3. beaker
4. metric ruler
Which piece of equipment could be
used to determine the mass of a
frog?
1. triple beam balance
2. graduated cylinder
3. beaker
4. metric ruler
Mass is best defined as the
1. size of an object
2. density of an object
3. amount of matter in an object
4. weight of an object
The amount of space an object
takes up is known as its
1. mass
2. density
3. volume
4. matter
The units for the volume of a
solid is
1. mL
2. mm
3. L
3
4. cm
The basic unit of volume in the
metric system is the
1. kilogram
2. gallon
3. liter
4. mass
• http://ippex.pppl.gov/interactive/matter/den
slab.html