The Metric System
The Metric System
• The metric system (International System of
Units) or SI System, is a universal system of
measurement used by scientists all over the
world.
– Based on multiples of 10
• Base Unit = 1
– Length = meter (1.0 m)
– Mass = gram (1.0 g)
– Volume = liter (1.0 L)
Prefixes and Suffixes
• Many words can be broken down into smaller
parts that can help you to better understand the
meaning of the word.
– Prefixes – terms attached to the beginning of a word.
• Preheat
– Pre means before
» To heat the oven before you cook something.
– Suffixes – terms attached to the end of a word.
• Laryngitis
– itis means inflammation
» A swelling or inflammation of the larynx or vocal cords.
Prefixes of the Metric System
Prefix
Unit
Fraction
Decimal
Kilo
One Thousand
1000
1000
Deci
One Tenth
1/10
.10
Centi
One
Hundredth
1/100
.01
Milli
One
Thousandth
1/1000
.001
Length
Unit
Abbreviation
Kilometer
km
Meter
m
Centimeter
cm
Millimeter
mm
Relationship
To Base Unit
1000 m
1.0
(Base Unit)
100 cm
(1/100 or .01)
1000 mm
(1/1000 or .001)
Length
• Length - How long something is.
– Instrument = metric ruler
– Base Unit = Meter (m)
(Base Unit)
(.1 or 1/10)
(.01 or 1/100)
(.001 or 1/1000)
Determining Length:
•How long is Example 1?
1.9 cm or 19 mm
•Which line is 50.0 mm in Length?
Line C
•Which line is .5 cm in length?
Line B
•How long is Line A?
3.6 cm or 36 mm
Mass
Unit
Symbol
Relationship
To Base Unit
Kilogram
kg
1000 g
Gram
g
Centigram
cg
Milligram
mg
1.0
(Base Unit)
100 cg
(1/100 or .01)
1000 mg
(1/1000 or .001)
Mass
• Mass - The amount of matter in an object
– Instrument = Triple Beam Balance
– Base Unit = Gram (g)
Reading A Triple Beam Balance:
Start with the largest beam, 100s, then add 10s and finish with the
smallest beam, 1s.
Solve the Problem:
200 + _____
70 + _____
6.5 = ______
276.5 g
_____
Reading A Triple Beam Balance:
100 + _____
30 + _____
3.3 = ______
133.3 g
_____
0 + _____
30 + _____
4.5 = ______
34.5 g
_____
Volume
Unit
Symbol
Relationship
To Base Unit
Kiloliter
kL
1000 L
Liter
L
1.0
(Base Unit)
Cubic centimeter
– (solid)
cm3
100 cm3
(1/100 or .01)
Milliliter
– (Liquid)
mL
1000 mL
(1/1000 or .001)
Volume
• Volume - The amount of space an object takes
up.
• 2 Types of Volume measurements:
– Solid Volume
• An object that has regular measurable sides.
– Liquid Volume
• An object that is a liquid or has irregular, nonmeasurable sides.
Solid Volume
• Instrument – metric ruler
• Base Unit – cubic meters (m3)
• Formula:
Volume = Length X Width X Height
• There are 3 measurements so you must have a
superscript of 3
Volume of a Solid
Formula: V = L X W X H
= 20 X 10 X 5
Work:
Answer:
V = 1000 cm3
Liquid Volume
• Instrument – Graduated Cylinder
• Base Unit – liter (L)
• Reading a Graduated Cylinder:
– Always take the reading
from eye level!
• Water in a container has
a curved surface or meniscus.
– Take the reading from the
bottom of the meniscus.
Measuring Liquid Volume
mL
15 mL
mL
18 mL
mL
20 mL
Irregularly Shaped Object
What is the volume of this ball?
Formula:
Volume = After – Before
Work:
= 65 - 40
40 mL
65 mL
Answer:
= 25 mL
mL
mL
Density
• Density - The measurement of how much
mass is contained in a given volume of an
object.
– Density is unique to each individual substance on
Earth.
• Water = 1 g/cm3 or 1g/mL
– Used to compare all other substances to:
» Anything greater than 1g/cm3 will sink
» Anything less than 1g/cm3 will float
Formula:
Density = Mass
Volume
Substance Densities
Substance
Aluminum
Vegetable Oil
Honey
Pine
Copper
Baby Oil
Density
2.7
.91
1.36
.5
8.96
.82
Sink or Float
Sink
Float
Sink
Float
Sink
Float
Finding Solid Density: (D = M/V)
1. A block of metal has a volume of 15 cm3 and
has a mass of 10 g. What is its density?
Formula:
Density = M/V
Work:
= 10 g / 15 cm3
Answer:
Density = .6 g/cm3
Would this substance sink or float? Float, less dense than
water
Finding Solid Density: (D = M/V)
2. A block of metal measures 4 cm X 4 cm X 4 cm
and has a mass of 75 g. What is its density?
Volume = l x w x h
=4X4X4
= 64 cm3
4cm
4cm
4cm
Formula: Density = M/V
Work:
= 75 g / 64 cm3
Answer:
3
= 1.2 g/cm
Would this substance sink or float? Sink, more dense
Than water
Solid Density
• If you were to cut a material in half would it’s density
change?
75g
37.5g
4cm
4cm
2cm
Formula: D = M/V
Work: 75g/64cm3
Formula: D = M/V
Work: 37.5g/32cm3
Answer:
Answer:
1.2g/cm3
1.2g/cm3
Liquid Density
Put the liquids in their correct from least dense to
most dense.
Liquid
Density
(g/mL)
A
.89
B
2.34
.89
1.0
C
1.21
D
1.0
1.21
2.34
What letter represents water? D, 1.0g/mL
Solid & Liquid Densities
• If a ball that has a density of 1.73 g/cm3 were
placed in the beaker, draw where the ball
would come to rest?
1.73 g/cm3
Solid & Liquid Densities
• If a block of wood has a density of .7 g/cm3
where would the block of wood be located in
this beaker of water?
.7 g/cm3