1. Chapter 1.4
Units of Measurement

2. Metric System Units for scientific measurements
Developed in France in 18th century
Unlike English system

3. SI Units 1960 international agreement Preferred metric units
7 base units

5. Prefixes
Decimal fractions
Multiples of various units
Ex: milli-

6. Prefixes of the Metric System

7. Length and Mass Length SI Unit  meter (m) 1 meter = 1.0936133 yd
Mass SI Unit  kilogram (kg)
1 kg = 2.2 lbs
Unusual use of prefix

8. Temperature
Hotness/coldness
Direction of heat flow
Celsius and Kelvin

9. Celsius Scale Everyday scale in most countries
Used often in scientific studies
0 C= Freezing point of water
100 C= Boiling point of water at sea level

11. Fahrenheit to Celsius
F = (9/5) (C) + 32
C = (5/9) (F - 32)

12. Kelvin Scale SI temperature scale Based on the properties of gases
Zero is the lowest obtainable temperature
Absolute Zero
0 K = C

13. Kelvin to Celsius
K = C

14. Derived SI Units Formulated from base SI Units
Example: speed has SI unit of m/s

15. Volume Derived SI Unit Cubic meters (m3)
Cubic centimeters (cm3) used in chemistry cc
1 milliliter = 1 cubic centimeter
1 mL = 1 cm3

16. Density Density = Mass/Volume Derived SI Unit g/cm3 g/mL
Always specify temperature when reporting density!! If no specification, assume 25C