September 28, 2016
3.2 Units of Measurement
Using SI Units
· All metric units are based on multiples of 10
- Makes conversion easy
· International system of Units (SI) - revised version of the
metric system
September 28, 2016
Choose the correct unit:
Cool thing about the metric system is:
1 L= 1000 mL = 1000 cm
3
& 1 mL of water = 1 g
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· Mass - the amount of matter in an object
· Weight - a force that measures the pull of gravity on a given
object's mass
· Energy - The ability to do work
- SI unit = Joule (J)
- more common unit is calorie (cal) - the quantity of heat
that raises the temperature of 1 g by 1oC
- 1 cal = 4.184 J
September 28, 2016
Temperature Scales
Temperature - measure of how hot or cold an object is
- Heat transfer is what makes stuff feel hot or cold
Celsius(oC) - Water freezes at 0oC & boils at 100oC
Kelvin (K) - absolute scale, water freezes at 273.15 K and
boils at 373.15 K
Absolute zero - where all molecular motion stops
K = oC + 273
oC = K - 273
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Density - ratio of an object's mass to its volume
Mass
__________
Density=
Volume
Density units = g/mL
September 28, 2016
Homework:
P 82 # 26-35