Name Period Date

SI Units

Scientists all over the world use the same system of units so they can communicate information clearly. This system of measurement is called the **International System of Units (SI)**. Metric measurement is based on the number ten and makes calculations with the system relatively easy. By using the following conversion chart, converting from one unit to another is done simply by moving the decimal point:

** Kilo- Hecto- Deca- _____ deci- centi- milli-**

The blank line in the middle of the conversion chart can change depending on what we are measuring:

The unit for length is the meter (m).

The unit for mass is the gram (g).

The unit for volume is the liter (L).

Part A

*What type of measurement is indicated by each of the following units? Choices are in the last column.*

Unit 1 – Intro to Physical Science 06/25/09

1. g/mL

2. s

3. km

4. g

5. cm3

6. mm

7. mg

8. L

9. g/cm3

density

length

mass

time

volume

Unit 1 – Intro to Physical Science 06/25/09

Part B

*For each of the following commonly used measurements, indicate its symbol. Use the symbols to complete the following sentences with the most appropriate unit. Units may be used more than once or not at all.*

Unit 1 – Intro to Physical Science 06/25/09

_____ milliliter

_____ kilogram

_____ meter

_____ milligram

_____ millimeter

_____ liter

_____ kilometer

_____ second

_____ centimeter

_____ gram

Unit 1 – Intro to Physical Science 06/25/09

1. Colas may be purchased in two or three _____ bottles.

2. The mass of a bowling ball is 7.25 _____.

3. The length of the common housefly is about 1 _____.

4. The mass of a paperclip is about 1 _____.

5. One teaspoon of cough syrup has a volume of 5 _____.

6. Stand with your arms raised out to your side. The distance from your nose to your outstretched fingers is about 1 _____.

7. On a statistical basis, smoking a single cigarette lowers your life expectancy by 642,000 _____, or 10.7 minutes.

**Part C – Conversion Factors**

1m = 100cm 1cm = 0.001m can also be written as 100cm or 1m__

This is called a conversion factor and it is =1

1m 100 cm

a. ______cm b. 1000mm c. ______m

1 m _____m 1km

d. ______sec e. _____ min f. ______hr g. ______days

1min 1hr 1 day 1 year

**C. To do conversions, the following work must be shown:**

Example 1: To convert 2.5 m to km you need to multiply 2.5m by the conversion factor (in the box) that will cancel off the metres.

2.5m x 1km =______km

1000m

Example 2: To convert 250 hours to days you will need to multiple 250 hours by the conversion factor (in the box) that will cancel off the hours.

250 hours x 1day = ______days

24 hours

**D. Now you try it, convert:**

1. 35 days to hours.

35 days x = ______hours

2. 250 cm to metres

250 cm x = ______m

3. 6 days to minutes

6 days x _____ hr x ___ min = ______min

1 day 1 hr

4. 1500 mm to km

1500 mm x 1cm__ x 1m x 1km = ______km

_____mm ____cm _____m

**E. Try these by yourself. – show all of the work **

1. 25 cm to km

2. 5 min to seconds

*Convert the following metric measurements: Show your Work by cancelling Units. *

1000 mg = _____ g 198g = _____ Kg 8 mm = _____ cm

160 cm = _____ mm 75 mL = _____ L 6.3 cm = _____ mm

109 g = _____ Kg 50 cm = _____ m 5.6 m = _____ cm

250 m = _____ Km 5 L = _____mL 26,000 cm = _____ m

14 Km = _____ m 16 cm = _____mm 56,500 mm = _____ Km

1 L = _____ mL 65 g = _____ mg 27.5 mg = _____ g

480 cm = _____ m 2500 m = _____ Km 923 cm = _____ m

27 g = _____ kg 355 mL = _____ L 0.025 Km = _____ cm

Name ANSWER KEY Period Date

Part A

*What type of measurement is indicated by each of the following units? Choices are in the last column.*

Unit 1 – Intro to Physical Science 06/25/09

10. g/mL density

11. s time

12. km length

13. g mass

14. cm3 volume

15. mm length

16. mg mass

17. L volume

18. g/cm3 density

density

length

mass

time

volume

Unit 1 – Intro to Physical Science 06/25/09

Part B

*For each of the following commonly used measurements, indicate its symbol. Use the symbols to complete the following sentences with the most appropriate unit. Units may be used more than once or not at all.*

Unit 1 – Intro to Physical Science 06/25/09

mL milliliter

kg kilogram

m meter

mg milligram

mm millimeter

L liter

km kilometer

s second

cm centimeter

g gram

Unit 1 – Intro to Physical Science 06/25/09

8. Colas may be purchased in two or three liter bottles.

9. The mass of a bowling ball is 7.25 kg.

10. The length of the common housefly is about 1 cm.

11. The mass of a paperclip is about 1 mg.

12. One teaspoon of cough syrup has a volume of 5 mL.

13. Stand with your arms raised out to your side. The distance from your nose to your outstretched fingers is about 1 m.

14. On a statistical basis, smoking a single cigarette lowers your life expectancy by 642,000 s, or 10.7 minutes.

Part C

*Convert the following metric measurements:*

1000 mg = **1 g 198g = 0.198 Kg 8 mm = 0.8** cm

160 cm = **1,600 mm 75mL = 0.075 L 6.3 cm = 63** mm

109 g = **0.109 Kg 50 cm = 0.50 m 5.6 m = 560** cm

250 m = **0.250 Km 5 L = 5,000mL 26,000 cm = 260** m

14 Km = **14,000 m 16 cm = 160mm 56,500 mm = 0.0565** Km

1 L = **1,000 mL 65 g = 65,000 mg 27.5 mg = 0.0275** g

480 cm = **4.8 m 2500 m = 2.5 Km 923 cm = 9.23** m

27 g = **0.027 kg 355 mL = 0.355 L 0.025 Km = 2,500** cm

Using Measurements – Ch. 2 CHEM