1. UNIT 2.2 SI UNITS/METRIC CONVERSIONS

2. SI UNITS SI = International system of metric units. Base unit = all other units are multiples of base units or combinations) QuantityWritten unitSymbol length mass time amount of substance

3. SI UNITS 2. MULTIPLES OF BASE UNITS (p.17) PrefixSymbolExponential megaM10 6 kilok10 3 decid10 -1 centic10 -2 millim10 -3 microμ10 -6

4. 10 6 10 3 10 -1 10 -2 10 -3 10 -6

5. 2.2 SI UNITS 3. IMPORTANT EQUIVALENCES 1 mL = 1 cm 3 1 m 3 = 10 3 L 1 t = 10 3 kg

6. 2.2 SI UNITS Example: Re-write the expression “6 kilograms” The prefix symbol for kilo is ___ The unit symbol for grams is ___ 6 kilograms = The exponential equivalent to kilo is ____ 6 kilograms =

7. METRIC CONVERSIONS Metric conversions involve using unit conversions between prefix symbols and exponential equivalents. Example: Write a conversion statement between cm and m.

8. M ETRIC CONVERSIONS Write conversion statements between each of the following dm and m cL and L dmol and mol

9. METRIC CONVERSIONS How many milligrams are in 5 kg? 5 kg = ? mg No direct link between kilo and milli What to do? Convert to a base unit first !

10. METRIC CONVERSIONS Express 7µm in Megametres 7µm =? Mm

11. M ETRIC CONVERSIONS How many decilitres in 0.5kL?

12. TRY 0.052 GHz = ? kHz Hz is Hertz( a frequency unit)

13. M ULTI C ONVERSION Convert 1cg/ mL into dg/L

14. M ULTI C ONVERSION TRY: Convert 3 mg/L into µ g/mL T

15. METRIC CONVERSIONS DERIVED QUANTITIES Derived quantity = Derived unit =

16. D ENSITY Density is an example of a derived unit What is density? Density =

17. D ERIVED UNITS : DENSITY Given that a 2.44 cm 3 sample of an element has a mass of 47.14 g. Determine the density of the element.

18. D ERIVED UNITS Find the volume of a block of wood that has a mass of 34.5 grams. The density of this wood is 12g/ cm 3

19. D ENSITY The density of carbon dioxide at standard temperature and pressure is 1.96 g/L. Calculate the mass of a 600 mL sample of carbon dioxide. The density of air is about 1.29 g/L at standard temperature and pressure. Would carbon dioxide tend to rise up or sink down in the atmosphere? _______________

20. Homework Hebden Page19 #13, 14, 15(a,c,d,f,g,i), Page 21 #16 (a,c,e) #17 (b,d,f,h,j,L,n) #18(a, b, c) Page 26 # 31,33, 37