Let’s revisit this idea!
Theory of Conservation of Matter:
Matter cannot be
created or destroyed!
What is matter?
Matter is anything that has mass
_______
and volume (takes up space).
Matter has mass and volume
Mass is the amount of matter in
_____
an object.
Matter has mass and volume
Volume is the amount of space
_______
an object takes up.
How is mass different from weight?
 The words mass and weight are often used as though
they mean the same thing, BUT THEY DO NOT!
 Weight = the measure of gravitational pull on an object
An object’s weight can change depending on its location. If the gravitational pull on the moon is
different, your weight on the moon will be different!
 Mass = mass tells you the amount of matter an object has
Your mass would not change on the moon. You are made up of the same amount of
atoms no matter where you are!
How much do I weight on the moon?
 Miss Lamb, due to the wonderful nature of gravity,
would only weigh 27.28 lbs. on the moon!
Woo hoo! Talk about an instant diet 
 Miss Lamb would, however, contain the same mass.
None of the atoms that make up my body would have
been destroyed in the process of traveling to the
moon. I would maintain my mass and shape.
Okay – So I may be happy that my mass didn’t change and I didn’t lose
anything necessary for living like an organ, but I wouldn’t mind if my
shape changed a bit ;)
A dog would have the same mass on the
moon!
The dog is made
up of the same
number of atoms
that all contain
their same atomic
masses!
Since mass is the
amount of matter
in an object, the
mass of the dog
stays the same. He
did not lose any
matter on the
journey to the
moon.
Weight…on the other hand…
Weight: a measure of the pull of gravity on an
object’s mass.
 Because of gravity, weight is NOT the same
everywhere in the universe. (on the moon you
would weigh less than Earth).
Let’s Explore This Idea Further…
 Using the triple beam balance, we will measure the mass of 5
small objects. Watch carefully as the teacher demonstrates how to
use this measuring device.
 Then, you will follow the steps one by one as the teacher completes
them. We will share our results together and make sure that
everyone is correctly calculating the mass.
 Please follow all of teacher’s instructions for using this balance. This
equipment is expensive to replace!
The triple beam balance
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Move all three sliders so that they read ‘zero’.
Make sure that there is nothing on the pan and
that it is clean.
Check to see if the balance reads zero.
Your balance isn’t reading zero so you need to
turn the thumbscrew to adjust the balance until
it reads zero
Your balance is ready to measure. Place object to
be weighed on the pan. Make sure that no part
of the object is supported by the table.
Move the sliders, beginning with the largest.
When moving a slider causes the balance to tip,
move the slider back to the previous position.
Move the next slider until it tips the balance.
Place is in the previous position.
Move the final slider until the balance reads
zero.
Read each of the sliders and add their weights
together. The unit should be recorded in grams.
What is the mass of…
 The black metal block?
 The marbles?
 The plastic blocks?
 The pennies?
 The pencil?
Let’s Explore This Idea Further…
 Now, using spring scales, we will measure the weight of 5 same
small objects. Watch carefully as the teacher demonstrates how to
use this measuring device.
 Then, you will follow the steps one by one as the teacher completes
them. We will share our results together and make sure that
everyone is correctly calculating the mass.
 Please follow all of teacher’s instructions for using this measuring
tool. The equipment is difficult to replace!
The Spring Scale
 Always zero out the scale
 Always use the scale right side
up
 Carefully place the items in the
bag or directly on the hook of
the scale
 Read the top of the indicator
 Each little line represents 20
grams or 1 N of force
What is the weight of…
 The black metal block?
 The marbles?
 The plastic blocks?
 The pennies?
 The pencil?
Are mass and weight the same thing?
We will now complete a side by side comparison.
Mass vs Weight [in grams]
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
metal block
These #s will need to
change. Any ideas on how
to set this up?
marbles
plastic blocks
mass
weight
pennies
pencil
Drawing Conclusions
 Write a sentence that describes the relationship between weight
and mass.
 The objects were not moving when you measured their weights.
What was balancing the force of gravity pulling them downward?
 When would the mass and weight of an object be different?
I know that matter takes up space, but what
is volume and how do I measure it?
 Volume is the amount of space an object
takes up
-A balloon and a bowling ball can have the
same volume, how can this be?
-Do they have the same mass?
How do we calculate volume?
Well defined shapes are easy to calculate:
Volume = length x width x height
How do we calculate volume?
 Irregular shapes are more difficult to
calculate.
 In this case, displacement can be
used to measure the volume of an
object
 Displacement works because no 2
objects can occupy the same space at
the same time. If you drop a rock into
a graduated cylinder, it will displace,
or move, the water. You can measure
the differences in the water level to
determine the volume of the object.