The SI System

Page
1

Slide 1

The SI System of Measurement

Slide 2

The Nature of Measurement

Part 1 - number

Part 2 - scale (unit)

Examples:

20 grams

6.63 x 10-34 Joule·seconds

A Measurement is a quantitative observation consisting of TWO parts

Slide 3

The Fundamental SI Units (le Système International, SI)

Slide 4

SI Prefixes Common to Chemistry

Slide 5

Metric Conversions

g

m

L

10-1

10-2

10-3

101

102

103

Base

unit

deci

centi

milli

deka

hecto

kilo

Conversions in the metric system are merely a matter of moving a decimal point. The “base unit” means the you have a quantity (grams, meters, Liters, etc without a prefix.

Slide 6

Metric Conversions

g

m

L

10-1

10-2

10-3

101

102

103

Base

unit

deci

centi

milli

deka

hecto

kilo

Example #1: Convert 18 liters to milliliters

18 L

1

2

3

18 liters = 18 000 milliliters

Slide 7

Metric Conversions

g

m

L

10-1

10-2

10-3

101

102

103

Base

unit

deci

centi

milli

deka

hecto

kilo

Example #2: Convert 450 milligrams to grams

1

2

3

450 mg

450 mg = 0.450 g

Slide 8

Metric Conversions

g

m

L

10-1

10-2

10-3

101

102

103

Base

unit

deci

centi

milli

deka

hecto

kilo

Example #3: Convert 20 kilograms to milligrams

20 kg

1

2

3

4

5

6

20 kg = 20 000 000 mg