1. Chemistry 20
September 7, 2012

2. SI Système international d’unités
AKA: The International system of units
Modern version of the metric system.

3. SI – Base Units Base Unit Name Common symbols What it measures Metre l
length
second t
time
mole n
Amount of substance
kilogram m
mass

4. SI - Prefixes
Prefixes can be added to base unit names to denote a multiple of that unit.
EX: 1000 metres = 1 kilometre
Please note that the base unit name for mass is the kilogram. For mass, although the base unit is the kilogram, we still denote things with prefixes on the word gram.
EX: 3000 grams = 3 kilograms

5. SI – Table of Prefixes 106 103 102 101 100 10-1 10-2 10-3 10-6 Name
Symbol
Factor
MULTIPLES
mega M
106
kilo k
103
hecto h
102
deca da
101
Base Unit
100
FRACTIONS
deci d
10-1
centi c
10-2
milli m
10-3
micro μ
10-6

6. SI - Staircase mega kilo hepto deca base deci centi milli micro

7. SI Examples
Convert to their base units
2301 cm
16000 g

8. Dimensional Analysis
Link to video

9. Dimensional Analysis - Examples
Convert 20 dollars to pounds (1 CAD = 0.63 GBP)
Convert 100 yards to metres (1 yard = metre)