1. Units of Measurement
2.2

2. Definitions Weight –measure of the gravitational pull on matter
Diff between mass and weight
Quantity – something that has magnitude, size or amount
Every measurement must have a unit
SI-Le Système International d’Unitès
We use 7 base units and prefixes to express all units

3. Quantity
Symbol
Unit
Abbreviation
Length l
Meter m
Mass
Kilogram kg
Time t
Second s
Thermodynamic Temperature T
Kelvin k
Amount of a Substance n
Mole
mol
Electric Current I
Ampere A
Luminous Velocity Iυ
Candela cd

4. Mega - M  (b.u.) = 1M(b.u.)
Kilo - k 1 000 (b.u.) = 1k(b.u.)
hecto - h  100 (b.u.) = 1h(b.u.)
deka - da  10 (b.u.) = 1da(b.u.)
Base Unit
deci - d  10 d(b.u.) = 1 (b.u.)
centi - c 100 c(b.u.) = 1 (b.u.)
milli - m 1 000 m(b.u.) = 1 (b.u.)
micro - µ  µ(b.u.) = 1 (b.u.)
nano - n n(b.u.)=1 (b.u.)

5. Derived Units Combination of SI base units
Examples – m3, g/cm3, kg/mol
Volume – the amount of space occupied by an object
1000mL = 1 L = 1000cm3

6. Conversion Factors
Ratio derived from the equality b/t 2 different units that can be used to convert from 1 unit to another
Ex: there are 4 quarters in 1 dollar
Dimensional analysis – math technique that allows you to use units to solve problems involving measurments

7. Conversion Factors
Quarters and dollars conversion factor – 4 quarters = 1 dollar
Convert 18 quarters to dollars
Start with what you know
What you are going to goes in the top and coming from goes in the bottom
Convert 3 dollars to quarters

8. Conversions
Convert 45 minutes to hours.
Convert 2.5 hours to minutes.
Convert 100 millimeters to meters
1 meter = 1000millimeters
Convert 3 hours to seconds

9. Conversions
Convert 0.12 kg to mg
Must convert to base unit first if going from one side to the other.
Convert 130 cm to Mm

10. Conversions with Derived Units
Convert 60 miles/hour to kilometers per second
1 mile = kilometers
How many grams per milliliter are there in 34 kilograms per liter

11. Density The ratio of mass to volume D = m Know this v equation!!!
Typically expressed as g/cm3.
Predict the order of the following from the most dense to the lease dense…
Milk, mercury, gasoline, ice, a diamond, a cork

12. Density Silver Bracelet
Mass is g and when it displaces water, volume is 20.5 cm3
Density of silver is 10.5 g/cm3
Is this a silver bracelet?

13. Density Calculations
A piece of an unknown material has a mass of 5.85 g and a volume of 7.57 cm3.  What is the density of the material?

14. Density Calculations D = m v D = m = 5.85 g v 7.57 cm3
Density = 0.77 g/cm3

15. Density calculations
A 200 g piece of metal has a volume of 25 cm3. Calculate the density of the metal.
An unknown mass of silicon occupies a volume of 350 cm3. Calculate the mass of Si knowing that the density of Si is 2.34 g/cm3.

16. Density
What is the volume that a 50 gram piece of gold occupies? The density of gold is 19.30g/cm3.

17. Density
A block of lead with dimensions of 2.0dm x 8.0cm x 35mm, has a mass of 6.356kg. Calculate the density of lead in g/cm3.

18. Density
A flask weighs g and is filled with 225 mL of carbon tetrachloride. The weight of the flask and carbon tetrachloride is found to be g. Calculate the density in g/ml and g/L

19. Density
A 28.5 g of iron shot is added to a graduated cylinder containing 45.5 mL of water. The water level rises to the 49.1 mL mark. Calculate the density.

20. Density
A cylindrical tube of length cm and radius of 2.00 cm is filled with argon gas. The empty tube weighs g. The tube filled with argon weighs g . Calculate the density.

21. Assignment Complete the section review on page 42 and do numbers 1-5.
This is due tomorrow!