lesson 2.2 and 2.3 metric prefixes (pages 16-23)
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LessonLesson2.2 and 2.32.2 and 2.3
Metric PrefixesMetric Prefixes(pages 16-23)(pages 16-23)
2.2 and 2.3 Learning Outcomes2.2 and 2.3 Learning Outcomes
Recognize base units Recognize base units Recognize metric prefixesRecognize metric prefixes To create CF by comparing base To create CF by comparing base
units to a metric prefixunits to a metric prefix To solve simple (1 CF) and complex To solve simple (1 CF) and complex
(2 or more CF) metric conversion (2 or more CF) metric conversion problemsproblems
Key Vocabulary WordsKey Vocabulary Words
SI unitsSI units Metric prefixMetric prefix Base unitBase unit Metric conversionsMetric conversions Derived unitDerived unit Derived quantityDerived quantity
Metric PrefixesMetric Prefixes
mass of Earth = 5.9742 × 1024 kilograms (kg) = 5.9742 x 1018 Gigagrams
We spend 1/3 of our life sleeping, that is 27.37 years, 8.6 x 108 seconds or 8.63 x 102 megaseconds (863 Msec)
Some more uses of metric prefixes
A Sloth’s top speed is 5 m/min = 0.3 km/hr or 5000 mm/min, or 83 mm/sec
2.2 Summery Notes2.2 Summery Notes::
The The International System of UnitsInternational System of Units is the is the modern form of the metric systemmodern form of the metric system
devised around the convenience of the number devised around the convenience of the number ten.ten.
world's most widely used systemworld's most widely used system Base units: a basic unit of measurement, all Base units: a basic unit of measurement, all
other units are multiples of the base unitother units are multiples of the base unit The base units are: Meter-m, gram-g (kg is the The base units are: Meter-m, gram-g (kg is the
actual SI unit… but in Chemistry we use the actual SI unit… but in Chemistry we use the gram), second- s, mole- mol, litre- L, tonne- tgram), second- s, mole- mol, litre- L, tonne- t
Prefixes are multiples of base units (see SWB Prefixes are multiples of base units (see SWB for all prefixes)for all prefixes)
Example:Example: Written Written prefixprefix
Prefix symbolPrefix symbol UnitUnit Unit symbolsUnit symbols Exponential Exponential equivalenequivalen
tt
cmcm centicenti cc metermeter mm 1010-2-2
kilogramkilogram
kmolkmol
GgGg
msms
microgramsmicrograms
dmdm
Example: Written prefix
Prefix symbol Unit Unit symbols Exponential equivalent
cm centi c meter m 10-2
kilogram kilokilo kk gramgram gg 101033
kmol kilokilo kk molemole molmol 101033
Gg gigagiga GG gramgram GG 101099
ms millimilli mm secondsecondss
ss 1010-3-3
micrograms micromicro uu gramgramss
gg 1010-6-6
dm decideci dd metremetre mm 1010-1-1
2.3 Summery Notes2.3 Summery Notes
1. Sample Question: How many 1. Sample Question: How many micrometers are there in 5 cm?micrometers are there in 5 cm?
2.3 Summery Notes2.3 Summery Notes
1. Sample Question: How many 1. Sample Question: How many micrometers are there in 5 cm?micrometers are there in 5 cm?
Plan: cmPlan: cmmmumum
2.3 Summery Notes2.3 Summery Notes
1. Sample Question: How many 1. Sample Question: How many micrometers are there in 5 cm?micrometers are there in 5 cm?
Plan: cmPlan: cmmmumum
# um = 5 cm x # um = 5 cm x 1 x 10 1 x 10-2-2 m m x x 1 um1 um
1 cm 1 x 10 1 cm 1 x 10-6-6 m m
= 5 x 10= 5 x 1044 um um
2. For every METRIC conversion 2. For every METRIC conversion use the following steps: U = I x CF use the following steps: U = I x CF
a.a. Identify the U and unitsIdentify the U and units
b.b. Identify the I and unitsIdentify the I and units
c.c. Identify all the CF(s)Identify all the CF(s)
d.d. Solve Solve For every metric conversion you must first For every metric conversion you must first
convert into the base unitconvert into the base unit In the CF, the In the CF, the prefix will always get the “1”prefix will always get the “1”
and the and the base will always get the exponential base will always get the exponential equivalent valueequivalent value
When you have a question that requires more When you have a question that requires more than one CF… make a plan!!than one CF… make a plan!!
The Metric Spider!! Get out your data booklet!!
The Metric Spider!!
Base Units
Metric Prefixes
m
mol
L
s
**g
t
Mega
M
Kilo
kmilli
m
micro
u
centi
cdeci
d
hecto
h
Giga
G
deka
da
nano
n
m
mol
L
s
**g
t
Meg
M
Kilo
kmilli
m
micro
u
centi
cdeci
d
hecto
h
Giga
G
deka
da
nano
n
109
106
103
102
101
10-9
10-6
10-3
10-2
10-1
=
=
=
=
==
=
=
=
=
See SWB pages 19-21 for examplesSee SWB pages 19-21 for examples
1. ONE STEP METRIC 1. ONE STEP METRIC CONVERSIONSCONVERSIONS
Example 1:Example 1:
a) Convert 9.4 nm into metres.a) Convert 9.4 nm into metres.
1. ONE STEP METRIC 1. ONE STEP METRIC CONVERSIONSCONVERSIONS
Example 1:Example 1:
a)a) Convert 9.4 nM into metres (nMConvert 9.4 nM into metres (nM m).m).
# m = 9.4 nM x # m = 9.4 nM x 1 x 101 x 10-9-9 m m
1 nM 1 nM
1. ONE STEP METRIC 1. ONE STEP METRIC CONVERSIONSCONVERSIONS
Example 1:Example 1:
Convert 9.4 nM into metres (nMConvert 9.4 nM into metres (nM m). m).
# m = 9.4 nM x # m = 9.4 nM x 1 x 101 x 10-9-9 m m = 9.4 x = 9.4 x 1010-9 -9 mm
1 nM 1 nM
2. TWO STEP METRIC 2. TWO STEP METRIC CONVERSIONSCONVERSIONS
TWO PREFIXES in the question. TWO PREFIXES in the question. These require the use of 2 CF.These require the use of 2 CF. Always convert to the base unit firstAlways convert to the base unit first..
Example 2:Example 2:
Convert 6.32 um into km.Convert 6.32 um into km.
2. TWO STEP METRIC 2. TWO STEP METRIC CONVERSIONSCONVERSIONS
Example 2:Example 2:
Convert 6.32 um into km Convert 6.32 um into km (um(ummmkm).km).
#km = 6.32 um x #km = 6.32 um x 1 x 101 x 10-6-6 m m x x 1 1 kmkm
1 um 1 x 101 um 1 x 1033 mm
2. TWO STEP METRIC 2. TWO STEP METRIC CONVERSIONSCONVERSIONS
Example 2:Example 2:
Convert 6.32 um into km Convert 6.32 um into km (um(ummmkm).km).
#km = 6.32 um x #km = 6.32 um x 1 x 101 x 10-6-6 m m x x 1 1 kmkm
1 um 1 x 101 um 1 x 1033 mm
= 6.32 x 10= 6.32 x 10-9-9 km km
3. DERIVED UNIT CONVERSIONS3. DERIVED UNIT CONVERSIONS
Example 3:Example 3:Convert 55.0 km/h into m/s.Convert 55.0 km/h into m/s.
3. DERIVED UNIT CONVERSIONS3. DERIVED UNIT CONVERSIONS
Example 3:Example 3:Convert 55.0 km/h into m/s.Convert 55.0 km/h into m/s.CF’s:CF’s: 1 km1 km 60 sec60 sec 1 h1 h1 x 101 x 1033 m 1 min 60 min m 1 min 60 min
Plan 1: Convert the numerator first: Plan 1: Convert the numerator first: KmKm m, m,
Plan 2: Convert the denominator second: Plan 2: Convert the denominator second: hh min min s s
I U
3. DERIVED UNIT CONVERSIONS3. DERIVED UNIT CONVERSIONS
Example 3:Example 3:Convert 55.0 km/h into m/s.Convert 55.0 km/h into m/s.
# m/s = 55.0 # m/s = 55.0 kmkm x x 1x101x1033 m m x x 1 1 hh x x 1 1 minmin
hh 1 1 kmkm 60 min 60 sec 60 min 60 sec
= 15. 3 m/s = 15. 3 m/s
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