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Metric System
Scientific Notation
In science, we deal with some very
LARGE numbers:
1 mole = 602000000000000000000000
In science, we deal with some very
SMALL numbers:
Mass of an electron =
0.000000000000000000000000000000091 kg
Scientific Notation:
A method of representing very large or
very small numbers in the form:
M x 10n
 M is a number between 1 and 10
 n is an integer
.
2 500 000 000
9 8 7 6 5 4 3 2 1
Step #1: Insert an understood decimal point
Step #2: Decide where the decimal must end
up so that one number is to its left
Step #3: Count how many places you bounce
the decimal point
Step #4: Re-write in the form M x 10n
2.5 x
9
10
The exponent is the
number of places we
moved the decimal.
0.0000579
1 2 3 4 5
Step #2: Decide where the decimal must end
up so that one number is to its left
Step #3: Count how many places you bounce
the decimal point
Step #4: Re-write in the form M x 10n
5.79 x
-5
10
The exponent is negative
because the number we
started with was less
than 1.
6
10
4 x
Multiply the front
6
x 3 x 10
numbers then add
12 x 1012 the exponents
1.2 x 1013
Move the decimal
behind the first
number
109
1.2 x
 3 x 104
0.4 x 105
4 x 104
Divide the front
numbers then
subtract the
exponents
Move the decimal
behind the first
number
SI System
 Standard International System of measurement – metrics
 Has seven base units and many other units derived from
these seven
Seven Base Units
Mass vs Weight
 Mass is not the same as weight
 Mass is the amount of matter in a substance
 Weight is a measure of the pull of gravity on the substance
 Can you be weightless? Can you be massless?
Derived Units
 Many other units are used in the metric system, but they are
combinations of the base units
 Speed - meter per sec (m/sec)
 Volume
volume = length x width x height
(m) x (m) x (m) = m3
.001 m3 = 1 liter (L)
1 cm3 = 1ml
Prefixes
 Metric system utilizes prefixes which indicate multiples of 10 of






the unit
kilohectodekadecicentimilli-
k
h
da
d
c
m
1000
100
10
.1
.01
.001
Converting Between Metric Units
3.65 dam = __________cm
2587 mm = __________hm
.0087 hl = __________cl
More Prefixes
Use the appropriate prefixes
3 x 106 L
15 x 10-9 g
8 x 108 m
3.5 x 10-6 A
1.46 x 1010 J
Temperature
 Metric unit – Kelvin – not used for measurement
 Measured in C (celsius)
 K = C + 273.15
 Old system is F (farenheit)
 C = 5/9 (F -32)
 What is 69 F in C and K?