1. Chapter 3: Measurement: SI and Metric

2. Objectives List SI units of measurement and common SI prefixes
Distinguish between base units and derived units
Convert between the Celsius and Kelvin temperature scales

3. International system of units
All measurements require units
Scientists use the 7 SI base units plus many other SI derived units

4. International system of units
Derived units
units that combine 2 or more of the base units
examples:
m x m = m2 (area)
m2 is a derived unit (it combines 2 base units of length)
kg x m / s2 = N (force)
N (newtons) is a derived unit (it combines 4 base units)

5. Metric prefixes
Often, units must be changed to make them smaller or larger
Metric prefixes do this by increasing or decreasing the size of the unit by a factor of 10

6. Metric prefixes
Commonly used metric prefixes in chemistry

7. Common units of length
Base unit for length is the meter (m), however we will use nanometers (nm) much more often when discussing the size of atoms and molecules

8. Common units of volume
Liter is a non-SI unit that is commonly used throughout the world to measure volume.
the size of a cube 10 cm long on each side
(10 cm) x (10 cm) x (10 cm) = 1000 cm3 = 1 L

9. Common units of mass
Base unit for mass is the kilogram (kg), however we will use the gram (g) or milligram (mg) much more often
Important relationship to know:
for water at 4C: 1 g = 1 cm3 = 1 mL

10. Temperature scales
On the Celsius scale, the freezing point of water is 0°C and the boiling point is 100°C.
On the Kelvin scale, the freezing point of water is kelvins (K), and the boiling point is K.
The zero point on the Kelvin scale, 0 K, or absolute zero, is equal to  °C.

11. Converting between scales
Because one degree on the Celsius scale is equivalent to one kelvin on the Kelvin scale, converting from one temperature to another is easy. You simply add or subtract , as shown in the following equations.
K = C
C = K

12. Converting between scales

13. Scientific notation
We will use scientific notation to represent very, very large or very, very small numbers.
3,000,000,000 m/s = 3 x 109 m/s
kg = 8.67 x 10-7 kg
Formula = m x 10n
m can only be numbers 1-9 with decimals
n is the number of places the decimal is moved
Positive if the decimal was moved to the left to get s.n.
Negative if the decimal was moved to the right to get s.n.