unit 2.2 si units/metric conversions. si units si = international system of metric units. base unit...
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UNIT 2.2SI UNITS/METRIC CONVERSIONS
SI UNITS
SI = International system of metric units.
Base unit = all other units are multiples of base units or combinations)
Quantity Written unit Symbol
length
mass
time
amount of substance
SI UNITS
2. MULTIPLES OF BASE UNITS (p.17)
Prefix Symbol Exponential
mega M 106
kilo k 103
deci d 10-1
centi c 10-2
milli m 10-3
micro μ 10-6
106
103
10-1
10-2
10-3
10-6
2.2 SI UNITS
3. IMPORTANT EQUIVALENCES
1 mL = 1 cm3
1 m3 = 103 L
1 t = 103 kg
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 =
METRIC CONVERSIONS
Metric conversions involve using unit conversions between prefix symbols and exponential equivalents.
Example: Write a conversion statement between cm
and m.
METRIC CONVERSIONS
Write conversion statements between each of the following
dm and m
cL and L
dmol and mol
METRIC CONVERSIONS
How many milligrams are in 5 kg?5 kg = ? mgNo direct link between kilo and milli What to do?
Convert to a base unit first !
METRIC CONVERSIONS
Express 7µm in Megametres 7µm =? Mm
METRIC CONVERSIONS
How many decilitres in 0.5kL?
TRY
0.052 GHz = ? kHz Hz is Hertz( a frequency unit)
MULTI CONVERSION
Convert 1cg/ mL into dg/L
MULTI CONVERSION
TRY: Convert 3 mg/L into µg/mL
T
METRIC CONVERSIONS
DERIVED QUANTITIES
Derived quantity =
Derived unit =
DENSITY
Density is an example of a derived unit What is density?
Density =
DERIVED UNITS: DENSITY
Given that a 2.44 cm3 sample of an element has a mass of 47.14 g. Determine the density of the element.
DERIVED UNITS
Find the volume of a block of wood that has a mass of 34.5 grams. The density of this wood is 12g/cm3
DENSITY
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? _______________
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