All measurements
in chemistry are made using the metric system. In using the metric system
often times you will have to convert between one unit and another. The
steps below show you how to convert between units using the label factor
method. There are other methods for converting between units. I prefer
this method because it will be used for other calculations later in the
year. For metric conversions use the chart below.
Metric
Conversions |
symbol |
prefix |
value |
conversion
factor |
G |
giga- |
109 |
10-9 |
M |
mega- |
106 |
10-6 |
K |
kilo- |
103 |
10-3 |
base units (gram/meter/liter) |
100 or
1 |
100 or
1 |
d |
deci- |
10-1 |
101 |
c |
centi- |
10-2 |
102 |
m |
milli- |
10-3 |
103 |
µ |
micro- |
10-6 |
106 |
n |
nano- |
10-9 |
109 |
p |
pico- |
10-12 |
1012 |
Note the difference
between the two columns on the right side of the chart below. The column
labeled value is the actual value of the metric unit. The column labeled
conversion factor is used only when converting between metric units. Please
see that the power of ten values in the conversion factor column have
the opposite sign of the power of ten values in the value column.
Example: Convert
18.3 kilograms to centigrams.
Step
1. Write the
given value and unit over 1.
18.3 kilograms
.........1
Step
2. Write a
multiplication sign . In this step, the numerator (on top) is the conversion
factor and unit to which you are converting. The denominator (on the bottom)
is the conversion factor and unit of the given number. Your problem should
be set up such that the given unit cancels out.
18.3 kilograms
x 102 centigrams =
.........1..............
10-3 kilograms
Step
3. Calculate
the problem. Remember when dividing powers of 10, subtract the denominator
from the numerator.
18.3 kilograms
x 102 centigrams = 18.3 x 105
.........1..............
10-3 kilograms
* (I got 105 by subtracting, 2 - (-3) = 5 )
Step
4. Put your
answer in proper scientific notation. 1.83 x 106
centigrams
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