UNIT II.2 & II.3 PPT

1. UNIT II.2 & II.3 PPT SI UNITS & METRIC CONVERSIONS

2. II.2 SI UNITS • SI = International system of metric units. • Base unit = basic unit of measurement • (all other units are multiples of base units or combinations) 1. BASE UNITS • length = metre (m) • mass = gram (g) • time = seconds (s) • amount of substance = mole (mol)

3. II.2 SI UNITS 2. MULTIPLES OF BASE UNITS • kilo = k (103) • centi = c (10-2) • milli = m (10-3) • **Table on page 17 – KNOW** 3. IMPORTANT EQUIVALENCES • 1 mL = 1 cm3 • 1 m3 = 103 L • 1 t = 103 kg

4. II.2 SI UNITS Example: • Re-write the expression “6 kilograms” using • PREFIX and UNIT SYMBOLS • an EXPONENTIAL EQUIVALENT • The prefix symbol that stands for kilo is ___ and the unit symbol that stands for grams is ___ • 6 kilograms = • The exponential equivalent to kilo is ____ • 6 kilograms = • Questions: p.19 #11-14

5. II.3 METRIC CONVERSIONS • Metric conversions involve using unit conversions between prefix symbols and exponential equivalents. Example: • Write a conversion statement between cs and s. • ‘c’ stands for _____ • then Questions: p.19 #15 (odds)

6. II.3 METRIC CONVERSIONS Example: • How many millimeters are in 5 km? • Unknown amount = • Initial amount = • Conversion factors = •  Combine conversion factors to make connection: • Solution

7. II.3 METRIC CONVERSIONS • Diagram (p. 20) – how prefix symbols relate to a central base unit:

8. II.3 METRIC CONVERSIONS Example 1: • Express 7µm in Megametres. Example 2: (p.21 #16e) • If 1 dL = 10-1 L and 1 kL = 103 L, how many decilitres in 0.5kL?

9. II.3 METRIC CONVERSIONS • Questions: p. 21 #16,17,18,24,28 DERIVED QUANTITIES • Derived quantity = • Derived unit = • Example on p. 23 • Question: p. 21 #29

10. II.3 METRIC CONVERSIONS Example 3: • Convert 1cg/ mL into dg/L • Unknown: • Initial: • Conversion factors = • Solution:

11. ASSIGNMENT