accuracy precision measurements scientific notation

1. Accuracy and Precision

2. Main Idea : Measurements may be
described as accurate and/or precise.
Essential Questions : How do
accuracy and precision relate to
reporting information?

3. Accuracy indicates how close a
measurement is to the true or accepted
value.
Precision refers to the closeness of
measurements within a set of data.

4. Scientific Notation

5. Main Idea : Some measurements are
conveniently expressed in scientific
notation.
Essential Questions : When is the
scientific notation advantageous to use?

6. Scientific
Notation
 In chemistry, we deal from very small
to very large quantities.
 We talk about size of nucleus, mass of
elementary particles, size of galaxies
and mass of black holes.
Size of proton =
0.00000000000000087 m
Speed of light = 299792458 m/s
 To work conveniently with such
extreme numbers, scientific notation
is used.
𝑎 × 10𝑥
Coefficient
Power

7. EXPRESSING A NUMBER IN SCIENTIFIC NOTATION
RULE 1 : Express the number as a number between 1 and 10 times a
power of 10.
RULE 2 : If the decimal point is moved to the left in the original
number, make the power of 10 positive.
RULE 4 : The power of 10 always equals the number of places
by which the decimal point has been shifted to the
left or right in the original number.
RULE 3 : If the decimal point is moved to the right in the original
number, make the power of 10 negative.

8. EXPRESSING A NUMBER IN SCIENTIFIC NOTATION
0.00000000000000087
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
8.7 × 10− 16
29979245
8
8 7 6 5 4 3 2 1
2 .998 × 10 8