Precision, Accuracy, & Significant
Digits
Scientific Notation
A method for expressing a given quantity as a number
having the significant digits necessary for a specified degree of accuracy,
multiplied by 10 to the appropriate power.
Scientific notation is helpful in writing very large
or very small numbers with few significant digits.
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written in Scientific Notation |
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has two parts:
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Example: |
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2,400
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the Coefficient
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the power of ten
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2.4
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x 103
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The decimal moved 3 places to the left.
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there is one number—
between 1 & 9—
to the left of a decimal.
No zeros ever go to the left of the decimal.
The only time zeros go to the right
of the decimal are when they are between numbers or the
zeros came at the end of a decimal number. |
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if the number is greater than one, then the exponent
is positive—and the decimal will move that number to the left.
<—
If the number is less than one,
then the exponent is negative—and the decimal
will move that number to the right. —> |
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Example: |
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0.018
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the Coefficient
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the power of ten
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1.8
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x 10-2
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The decimal moved 2 places to the right.
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Powers of Ten
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10 x 10 x 10
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103
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10 x 10
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102
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10
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10 or 101
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0
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100
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1/10
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10-1
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1/10 x 1/10
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10-2
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1/10 x 1/10
x 1/10
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10-3
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Example:
To write the measurement 23,000 °C in scientific notation,
move the decimal from the end of the number to right after the 2 — that
is 4 spaces to the LEFT.
That gives you a coefficient of 2.3
For the power of ten, since the decimal was moved 4 spaces
to the left, the exponent on the power of ten is a 4.
Therefore, 23,000 °C = 2.3 x 104
°C
What is Scientific Notation?
Practice Problems
Answer the following questions: |
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1. |
What are the two parts of a number written
in scientific notation? |
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2. |
Restate the following measurements in scientific
notation: |
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a) 350 g |
b) 0.000 16 L |
c) 5,220,000 m |
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d) 425,000 K |
e) 0.000 000 8 s |
g) 3,050 g/mL |
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3. |
Restate the following measurements in scientific
notation: |
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a) 4.9 x 10-4
s |
b) 5.5 x 104
°C |
c) 3.25 x 102
g |
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d) 6 x 106
m |
e) 7 x 10-5
m |
f) 1.2 x 10-3
g |
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4. |
Can a zero ever go to the left of
the decimal in the coefficient of a number written in scientific notation?
Can a zero ever go to the right of the decimal
in the coefficient of a number written in scientific notation? |
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5. |
If the original measurement is ten thousand
kelvin, which direction will the decimal move, and what will be the exponent
in the power of ten? Is the exponent positive or negative? |
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6. |
If the original measurement is one thousandth
of a meter, which direction will the decimal move, and what will be the
exponent in the power of ten? Is the exponent positive or negative? |
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Sources: CHEMISTRY - an Introduction to General, Organic, &
Biological Chemistry, Prentice Hall CHEMISTRY, Modern CHEMISTRY,
CHEMISTRY
- the Central Science, and Principles & Applications of CHEMISTRY |