1. Unit 1 NOS PPT #3 Metric SI measurements
Le Système international d'unités
The only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly
Among countries with non-metric usage, the U.S. is the only country significantly holding out. The U.S. officially adopted SI in 1866.
Information from U.S. Metric Association

2. Chemistry In Action
On 9/23/99, $125,000,000 Mars Climate Orbiter entered Mars’ atmosphere 100 km lower than planned and was destroyed by heat.
1 lb = 1 N
1 lb = 4.45 N
“This is going to be the cautionary tale that will be embedded into introduction to the metric system in elementary school, high school, and college science courses till the end of time.”

3. Standards of Measurement
When we measure, we use a measuring tool to compare some dimension of an object to a standard.
For example, at one time the standard for length was the king’s foot. What are some problems with this standard?

4. In every measurement there is a Number followed by a
Stating a Measurement
In every measurement there is a
Number followed by a
Unit from a measuring device
The number should also be as precise as the measurement!

5. UNITS OF MEASUREMENT Use SI units — based on the metric system Length
Mass
Volume
Time
Temperature
Meter, m
Kilogram, kg
Liter, L
Seconds, s
Celsius degrees, ˚C
kelvins, K

6. Mass vs. Weight
Mass: Amount of Matter (grams, measured with a BALANCE)
Weight: Force exerted by the mass, only present with gravity (pounds, measured with a SCALE)
Can you hear me now?

7. Some Tools for Measurement
Which tool(s) would you use to measure:
A. temperature
B. volume
C. time
D. weight

8. Learning Check M L M V Match L) length M) mass V) volume
____ A. A bag of tomatoes is 4.6 kg.
____ B. A person is 2.0 m tall.
____ C. A medication contains 0.50 g Aspirin.
____ D. A bottle contains 1.5 L of water. M L M V

9. Learning Check
What are some U.S. units that are used to measure each of the following?
A. length
B. volume
C. weight
D. temperature

10. Metric Prefixes Kilo- means 1000 of that unit
1 kilometer (km) = meters (m)
Centi- means 1/100 of that unit
1 meter (m) = 100 centimeters (cm)
1 dollar = 100 cents
Milli- means 1/1000 of that unit
1 Liter (L) = milliliters (mL)

11. Metric Prefixes

12. Metric Prefixes

13. How many jumps does it take?
Ladder Method 1 2 3
KILO 1000 Units
HECTO 100 Units
DEKA 10 Units
DECI 0.1 Unit
Meters Liters Grams
CENTI 0.01 Unit
MILLI Unit
How do you use the “ladder” method?
1st – Determine your starting point.
2nd – Count the “jumps” to your ending point.
3rd – Move the decimal the same number of jumps in the same direction.
4 km = _________ m
Starting Point
Ending Point
How many jumps does it take? 4. 1
__. 2
__. 3
__.
= 4000 m

14. Conversion Practice Try these conversions using the ladder method.
1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm
14 km = _______ m 109 g = _______ kg 250 m = _______ km
Compare using <, >, or =.
56 cm m 7 g mg

15. Learning Check Select the unit you would use to measure 1. Your height
a) millimeters b) meters c) kilometers
2. Your mass
a) milligrams b) grams c) kilograms
3. The distance between two cities
a) millimeters b) meters c) kilometers
4. The width of an artery

16. Learning Check 1. 1000 m = 1 ___ a) mm b) km c) dm
g = 1 ___ a) mg b) kg c) dg
L = 1 ___ a) mL b) cL c) dL
m = 1 ___ a) mm b) cm c) dm

17. Units of Length ? kilometer (km) = 500 meters (m)
2.5 meter (m) = ? centimeters (cm)
1 centimeter (cm) = ? millimeter (mm)
1 nanometer (nm) = 1.0 x 10-9 meter
O—H distance =
9.4 x m
9.4 x 10-9 cm
0.094 nm

18. Metric Conversion Challenge
Write the correct abbreviation for each metric unit.
1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____
2) Meter _____ 5) Millimeter _____ 8) Centimeter _____
3) Gram _____ 6) Liter _____ 9) Milligram _____
Try these conversions, using the ladder method.
10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm
11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km
12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg
13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm
14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

19. Compare using <, >, or =.
25) 63 cm m 27) 5 g mg 29) 1,500 mL L
26) 536 cm dm 28) 43 mg g 30) 3.6 m cm