1 5 NOTES Scientific Measurement Why is it

1. 5 NOTES Scientific Measurement

Why is it important to standardized measurement? (Propofol – used for sedation and anesthesia)

What’s the problem? Really? What?

The Metric System • SI Units: International System of Units (Metric!) • 1. Standard Base Units (SI base units). Seven basic units from which all other units are derived • Time: second • Length: meter • Mass: kilogram • Amount of Substance: mole • Temperature: Kelvin • Current: ampere • Luminous Intensity: candela

Derived units • Units that are combinations/derivatives of SI Base Units based on mathematical relationships. • Examples: volume (L x W x H, m 3), area (L x W, m 2), velocity (m/s), density (g/m. L)

• The formula can be rearranged to solve for any of the variables • Example 1: What is the volume of a sample that has a mass of 20 grams and a density of 4 g/m. L? D = m/v v = m/D = 20. 0/4. 0 = 5. 0 m. L • Example 2: A piece of metal with a mass of 147 g is placed in a 50 m. L graduated cylinder. The water level rises from 20 m. L to 41 m. L. What is the density of the metal • D = m/v = 147 g/(41. 0 -20. 0) = 147/21. 0 = 7. 00 g/m. L

Scientific Notation • Scientific Notation: Shorthand for large or small numbers. • Writing in Scientific Notation: Move the decimal so only one nonzero digit is to the left of the decimal. (If the number is larger than one, the decimal moves to the left; smaller than one, the decimal moves to the right. ). The exponent will be positive if the number is larger than one and negative if less than 1.

• Examples – Convert to scientific notation or to standard form. Remember to retain significance. a. 700. m b. 5, 000, 000 kg c. 0. 00023 kg d. 0. 000 80 cm e. 2. 40 x 105 f. 1. 730 x 10 -3 g. 2. 780 x 107

Calculating with scientific notation • ***Know how to use the EE button on your calculator*** • 3. 4 x 102 3. 4 E 2 • 4. 50 x 1034 4. 50 E 34

Scientific Notation • Adding and subtracting • The exponent must be the same for all numbers you are adding and subtracting • Add the decimal portion together and keep the exponent the same • Examples: • + • 5. 2 X 106 1. 3 X 106 - 8. 14 X 109 6. 01 X 109 + 1. 2 X 103 1. 2 X 104

Scientific Notation • Calculating with Scientific Notation • When multiplying, multiply coefficients first, then ADD the exponents. • When dividing, divide coefficients first, then SUBTRACT the exponents. • Examples: • (6 X 103) X (1 X 106) = (1. 2 X 103) X (4. 1 X 102) = • (1. 2 X 10 -2) X (4. 1 X 10 -4) =

Scientific Notation Examples: 8 X 106 4 X 104 9 X 103 3 X 10 -3

Metric Prefixes Prefix Meaning - Example Kilo Hecta Exponential Factor 103 102 Deka 101 10 m = 1 decameter Base Unit Deci Centi 100 1 meter = 1 meter 10 -1 10 -2 . 1 meter = 1 decimeter. 01 meter = 1 centimeter Milli 10 -3 . 001 meter = 1 millimeter 1 000 m = 1 kilometer 100 m = 1 hectometer

• Prefixes are used to represent quantities that are larger or smaller than the base units

Metric Prefixes • When you convert between two units, move the decimal. When going from a small unit to a larger unit, your number should get smaller. When going from a large unit to a smaller unit, the number should get smaller. • King Henry Died By Drinking Chocolate Milk • • Kilo Hecta Deka Base Deci Centi Milli • G · · M · · k h da Base d c m · · μ · · n Å

Metric Prefixes G · · M · · k h da Base d c m · · μ · · n Å • Examples: • 2. 44 cm km 3. 57 g mg • 14 dam hm 5. 46 • . 123 mg Å d. L k. L