Metric System

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Metric System
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International System of Measurement

• Base Units from which all other units are
  derived
• Meter length m
• - one ten millionth of the distance
• from the equator to the pole

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• Mass kilogram kg
• - amount of matter in an object
• - not the same as weight (which is a
• measure of gravity)

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Derived Unit

• Volume liter L
• - combination of three length units
• 1 cm3 1 ml
• 1000 cm3 1 L

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Prefixes

• 3.65 dam ________cm
• 2587 mm ________hm
• .0087 hl _________cl

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More Prefixes

• Mega- M 106
• Micro- u 10-6
• Nano - n 10-9
• Pico- p 10-12

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Use the appropriate prefixes

• 3 x 106 L
• 15 x 10-9 g
• 8 x 108 m
• 3.5 x 10-6 A
• 1.46 x 1010 J

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Conversion Factors

• Equality used to make conversions from one unit
  to another

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Practice

• There are 3.5 lb of NaCl, how many kg are there?
• You have 2.0 yd3 of concrete, what is this in m3?
• You are driving at 40 km/hr, what is this in
  m/sec?

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Temperature

• Metric unit Kelvin not used for measurement
• Measured in ?C (celsius)
• K ?C 273.15
• Old system is ?F (farenheit)
• C 5/9 (F -32)
• What is 69 ?F in ?C and K?

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• Temperature is an intensive property- does not
  depend on the amount
• Extensive properties so depend on the amount
• In the statement a yellow sample is solid at 25
  C. It weighs 6.0g and has a density of 2.3g/cm3
  what are the intensive and extensive properties?

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Conversions

• Often the units must be changed in order to do a
  problem
• Conversion factor method Is utilized

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Examples

• If 2.54 cm are in one inch, how many cm in 118
  in?
• If there are .24L in one cup, how many liters in
  26 cups?
• If 3.8 L 1 gal, how many L in 6.5 gal?