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SI units,prefixes, and valuesP. Perkerson
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol
Measuring Instrument
mass
length
time
temperature
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol
Measuring Instrument
mass gram or kilogram
gkg
length meter m
time second s
temperature
kelvin K
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol
Measuring Instrument
mass gram or kilogram
gkg
balance
length meter m
time second s
temperature
kelvin K
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol
Measuring Instrument
mass gram or kilogram
gkg
balance
length meter m ruler
time second s
temperature
kelvin K
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol Measuring Instrument
mass gram or kilogram
gkg
balance
length meter m ruler
time second s watchor clock
temperature kelvin K
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol
Measuring Instrument
mass gram or kilogram
gkg
balance
length meter m ruler
time second s watchor clock
temperature kelvin K thermometer
amount of substance
International System of Units – Base Units (Page 130)
Quantity Unit name Unit Symbol Measuring Instrument
mass gram or kilogram
gkg
balance
length meter m ruler
time second s watchor clock
temperature kelvin K thermometer
amount of substance
mole mol can’t be measured directly
SI prefixesname symbol meaning ratio to
base unit
giga
mega M 1 million106
kilo k 1 thousand103
SI prefixesname symbol meaning ratio to
base unit
giga G 1 billion109
mega M 1 million106
kilo k 1 thousand103
SI prefixesname symbol meaning ratio to
base unit
giga G 1 billion109
109 base units
1 giga unit
mega M 1 million106
106 base units
1 mega unit
kilo k 1 thousand103
103 base units
1 kilo unit
SI prefixesname symbol meaning ratio to
base unit
deci d 1 tenth (0.1)10-1
centi c 1 hundredth
(0.01)10-2
milli m 1 thousandth(0.001)
10-3
SI prefixesname symbol meaning ratio to
base unit
deci d 1 tenth (0.1)10-1
10 deci units1 base unit
centi c 1 hundredth
(0.01)10-2
100 centi units1 base unit
milli m 1 thousandth{0.001)
10-3
1000 milli units1 base unit
SI prefixesname symbol meaning ratio to
base unit
micro 1 millionth10-6
nano n 1 billionth10-9
pico p 1trillionth
10-12
SI prefixesname symbol meaning ratio to
base unit
micro 1 millionth10-6
106 micro units
1 base unit
nano n 1 billionth10-9
109 nano units
1 base unit
pico p 1trillionth
10-12
1012 pico units
1 base unit
Derived unitsDerived from base unitsVolume is derived from length base unit
V = l x w x hV = length unit cubed = m3
Volume
m3 is not a very handy unit – especially if you are dealing with liquids
“new” derived unit liter (L)
Liter definitions1000 L = 1 m3
1 L = 1m3/10001 L = 1 dm3
1 L = 1000 mL1 mL = 1 cm3 = 1cc
Density is also a derived unit –D = M/V
Pure water has a density of 1 g/mL (at room temperature)
What are units based on?Meter: since 1983, based on distance traveled
by light in 1/299,792,458 sec.Kilogram: mass of 1 cubic decimeter of water.
Second: old -1/86,400 of a solar day – now – The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
Kelvin: unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.
Mole: the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12; its symbol is "mol." One mole is equal to 6.02 X 1023 “things”.
