Measuring Matter

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Measuring Matter

2.  Weight is a measure of the force of gravity on a
person or thing.
 On Earth all objects are attracted downward by
Earth’s gravity.
 In everyday life, weight is a useful
measurement of how much matter an object
contains.
Mass vs. Weight

3.  On other planets or on the moon, the force of
gravity is far less or even non-existent.
 Scientists rely on a property that is consistent
regardless of where the object may be located
and this property is called mass.
 Mass is the measurement of how much matter
an object contains.
 An object’s weight will change if you move it
from Earth to the moon or to other planets, but
its mass will stay the same.

4.  To measure the properties of matter, scientists
use a system of units called the International
System of Units. (SI)
 For mass, the SI unit is the kilogram (kg).
 Although you may see things measured in
kilograms, the most common way to measure
mass is in grams. (g)
 There are exactly 1000 grams in one kilogram
Units of Mass

5.  The amount of space that an object takes up is
called volume.
 It is easy to see the amount of space a solid or a
liquid takes up, but gases are have volume too.
 When you blow up a balloon you can see that
your breath has volume.
 To find the volume of a rectangular object the
following equation must be used: Volume=
Length X Width X Height.
Volume

6.  If the object is measured using centimeters, the
final unit will be cubic centimeters. (cm3)
 Other common units of volume are liters (L)
and milliliters (mL).
 A milliliter is exactly 1 cubic centimeter and
there are 1000 milliliters in one liter.

7.  To find the volume of an irregular shaped
object, the object can be placed in a graduated
cylinder containing water.
 Measure the amount of water in the graduated
cylinder before the object is placed in the water
and after the object is placed in the water.
 Subtract the first reading from the second
reading to find the object’s volume.
 https://www.youtube.com/watch?v=n3ia4i-
uFTM

8.  Different substances may have the same mass,
but they don’t necessarily fill the same volume.
 Density is the measurement of how much mass
is contained in a given volume.
 To calculate the density of an object, divide its
mass by its volume.
 Density= Mass/Volume
Density

9.  One typical unit of density is written as g/cm3.
 The density of a substance is the same for all
samples of that substance.
 For example, all samples of gold regardless of
size have a density of 19.3 g/cm3.
 Density is another example of a characteristic
property.

10.  https://www.youtube.com/watch?v=kE8I_M2p
yg8

 http://phet.colorado.edu/sims/density-and-
buoyancy/density_en.html
 http://phet.colorado.edu/en/simulation/states-
of-matter-basics
Links to Check Out

11.  Why are mass and weight different
measurements?

 What two quantities do you need to know in
order to calculate density?

 Describe how you would measure the volume
of an object with a n irregular shape.
Review