Stating a Measurement
In every measurement there is a
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Number followed by a
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Unit from a measuring device

 adopted in 1960
 seven base units which all others can be derived
 m, kg, K, s, mol, cd, A

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Le Système international d'unités
The only countries that have not
officially adopted SI are Liberia
(in western Africa) and Myanmar
(a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly
Metrication is a process that does not happen all at once, but is rather a process that happens over time.
Among countries with nonmetric usage, the U.S. is the only
country significantly holding out.
The U.S. officially adopted SI in
1866.
Information from U.S.
Metric Association

Common Metric Prefixes

 properties are that it has:
 mass: amount of matter (atoms) in an object
 volume: amount of space an object takes up
 density: the mass per unit volume of an object
What some things that are not matter?

 Length
 a linear measurement
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 meter (m) common units- cm, m, km

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 space occupied by a sample of matter cubic meter (m 3 ) but we use the non SI unit liter (L) most of the time instead common units- L, ml, cm 3 , µL should be measured at 0 ° C

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 this in NOT weight
 measures the quantity of matter
 kilogram (kg)
 common units- kg, g, mg, µg

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 measures kinetic energy of particles kelvin (K)
 common units are K and °C
Notice that 1 Kelvin = 1 degree Celsius
Anders Celsius
1701-1744
Lord Kelvin
(William Thomson)
1824-1907

Learning Check
Match L) length M) mass V) volume

 an intensive or intrinsic
property of matter
 the ratio of an object’s mass to its volume
 depends on only on the substance, NOT ON THE
SIZE of the substance
 as temperature increases, density normally decreases
(thermal expansion)
Back to the
Future
“Your are my density” clip. Back to the Future
“Your are my density” clip

D = M/V

•
A piece of lead has a mass of 56.4 g and a volume of 5.3 cm 3 . Calculate its density.
given formula set up problem answer w/ unit of measurement
M= 56.4 g
V= 5.3 cm 3
D=M/V 56.4g/5.3 cm 3 11 g/cm 3 cm 3 is same as ml so sometimes see g/ml

Density
 mass (g) volume (cm3)
Platinum
Mercury
Aluminum
13.6 g/cm 3 21.5 g/cm 3 2.7 g/cm 3