1. Chapter 1 Chemistry and Measurements
1.7
Prefixes and Equalities

2. Prefixes
A special feature of the SI as well as the metric system is that a prefix can be placed in front of any unit to increase or decrease its size by some factor of ten.
For example, the prefixes milli and micro are used to make the smaller units:
milligram (mg)
microgram (μg)

3. Prefixes and Equalities
The relationship of a prefix to a unit can be expressed by replacing the prefix with its numerical value.
For example, when the prefix kilo in kilometer is replaced with its value of 1000, we find that a kilometer is equal to meters.
kilometer = 1000 meters
kilogram = 1000 grams

4. Prefixes That Increase Unit Size

5. Prefixes That Decrease Unit Size

6. Learning Check Fill in the blanks with the correct prefix:
A m = 1 ___m
B. 1 x 10−3 g = 1 ___g
C m = 1 ___m

7. Solution Fill in the blanks with the correct prefix:
A m = 1 ___m
The prefix for 1000 is kilo; 1000 m = 1 km
B. 1 x 10−3 g = 1 ___g
The prefix for 1 x 10−3 is milli; 1 x 10−3 g = 1 mg
C m = 1 ___m
The prefix for 0.01 is centi; 0.01 m = 1 cm

8. Measuring Length
Each of the following equalities describes the same length in a different unit. 1 m = 100 cm = 1 x 102 cm 1 m = 1000 mm = 1 x 103 mm 1 cm = 10 mm = 1 x 101 mm

9. Measuring Length
The metric length of 1 meter is the same as 10 dm, 100 cm, or 1000 mm.

10. Measuring Volume
Examples of Some Volume Equalities 1 L = 10 dL = 1 x 101 dL 1 L = 1000 mL = 1 x 103 mL 1 dL = 100 mL = 1 x 102 mL

11. The Cubic Centimeter
The cubic centimeter (abbreviated as cm3 or cc) is the volume of a cube whose dimensions are 1 cm on each side. A cubic centimeter has the same volume as a milliliter, and the units are often used interchangeably. 1 cm3 = 1 cc = 1 mL

12. 1 cm3 = 1 cc = 1 mL 10 cm x 10 cm x 10 cm = 1000 cm3 = 1000 mL = 1 L
The Cubic Centimeter
1 cm3 = 1 cc = 1 mL 10 cm x 10 cm x 10 cm = 1000 cm3 = 1000 mL = 1 L

13. Measuring Mass
Examples of Some Mass Equalities 1 kg = 1000 g = 1 x 103 g 1 g = 1000 mg = 1 x 103 mg 1 g = 100 cg = 1 x 102 cg 1 mg = 1000 μg = 1 x 103 μg

14. Learning Check
Identify the larger unit in each of the following: A. mm or cm B. kilogram or centigram C. mL or μL

15. Solution
Identify the larger unit in each of the following: A. mm or cm A mm is m, smaller than a cm, 0.01 m. B. kilogram or centigram A kilogram is 1000 g, larger than a centigram or 0.01 g. C. mL or μL A milliliter is L, larger than a μL, L.