Bell Ringer1. Round 37050 kg to 3 sig figs.2. What is the rule for addition and

subtraction?3. What is the rule for multiplication and

division?4.

(12 x 3.5 + 0.451)

(3.24 x 5.123)

Elements Quiz

Period

9/9 Tuesday

2nd 55

3rd 66

4th 63

5th 56

6th 51

Elements Quiz You need a pen or pencil

Once done with your quiz, please take out your sig figs calculations hw

MeasurementsMeasurements

Metric (SI) unitsMetric (SI) units PrefixesPrefixes UncertaintyUncertainty

Significant figures

Significant figures

Conversionfactors

ConversionfactorsLengthLength

DensityDensity

MassMass VolumeVolume

Problem solving withconversion factors

Problem solving withconversion factors

SI Base UnitsBase Quantity Name

SymbolLength meter mMass kilogram    kgVolume Liter LTime second stemperature       Kelvin Kamount of substance mole molelectric current ampere Aluminous intensity candela cd

MeasurementsMeasurements

Metric (SI) unitsMetric (SI) units PrefixesPrefixes UncertaintyUncertainty

Significant figures

Significant figures

Conversionfactors

ConversionfactorsLengthLength

DensityDensity

MassMass VolumeVolume

Problem solving withconversion factors

Problem solving withconversion factors

Exact Numbers Considered to have an infinite number

of significant figures Ex. “There are 4 quarts in a gallon”, the

number 4 would be exact Ex. “A is two times as large as B”, the

number 2 would be exact Usually involve counted values,

conversion factors, or definitions

MeasurementsMeasurements

Metric (SI) unitsMetric (SI) units PrefixesPrefixes UncertaintyUncertainty

Significant figures

Significant figures

Conversionfactors

ConversionfactorsLengthLength

DensityDensity

MassMass VolumeVolume

Problem solving withconversion factors

Problem solving withconversion factors

PrefixesYou must know: kilo = 1000 centi = 1/100 milli = 1/1000

Useful in future: Mega = 106

nano = 10-9

pico = 10-12

Fill in the missing numbers 1 kg = ____ g 1g = ____ cg 1g = ____ mg

1 km = ____ m 1 m = ____ cm 1 m = ____ mm 1 cm = ____ mm

1L = ____ mL 1mL = ____ cm3

MeasurementsMeasurements

Metric (SI) unitsMetric (SI) units PrefixesPrefixes UncertaintyUncertainty

Significant figures

Significant figures

Conversionfactors

ConversionfactorsLengthLength

DensityDensity

MassMass VolumeVolume

Problem solving withconversion factors

Problem solving withconversion factors

Dimensional Analysis (aka conversions) Def: method of calculation utilizing a

knowledge of units where conversion factors are used to manipulate units

The conversion factors are simple ratios

Ex: 1 hr = 60 min, 1 mol = 6.022 x 1023 atoms

Steps to Dimensional Analysis What data are we given? What quantity do we need (our unknown)? What conversion factors are available to

take us from what we are given to what we need?

[perform calculation] Does our answer make sense?

Factor Label Method(used in all chemistry and physics classes. Save yourself lots of grief and learn it now!) Remember these two ideas:

1. Any number can be multiplied by 1 without changing its value.

2. Multiplying by a conversion factor is like multiplying by 1 because the numerator and the denominator are equal.

Ex.

Let’s do some together!1. Ms. B’s college ring weighs ______ g. How

many kg is this?

2. Convert 2 L of Monster to mL.

3. Convert 2.5 kg to mg.

Crash Course Chemistry https://

www.youtube.com/watch?v=hQpQ0hxVNTg

3:07-5:18

Whiteboard Race How many L is 36.2 mL?

Whiteboard Race How many teaspoons are in a liter bottle

of Sprite? 1tsp = 4.93mL

Whiteboard Race Wes speeds down the hallway at a

whopping 4 miles per hour. How many km/s is he travelling?

Whiteboard Race You scrounge up the money to by a

Jaguar (the car, not the animal…). You’re going down the highway with your speedometer reading 47 km/hr. Are you speeding if the speed limit is 60 miles/hr?

Whiteboard Race In a primitive barter society, the

following rates of exchange exist:1 fot = 5 vum 2 sop = 3 tuz4 bef = 3 tuz 9 fot = 2 bef

A woman has 4 sop and wants to convert all her possessions into vum. How many vum can she trade for?

Exit Ticket (turn in on the way out) Convert 8.4x10-2cm to mm.

Convert 5 ft to cm. (1 in = 2.54 cm)