Bell Ringer Round 37050 kg to 3 sig figs. What is the rule for addition and subtraction? What is the rule for multiplication and division? (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

Measurements Conversion factors Significant figures Density Metric (SI) units Prefixes Uncertainty Length Mass Volume Conversion factors Significant figures Density Problem solving with conversion factors

SI Base Units Base Quantity Name Symbol Length meter m Mass kilogram kg Volume Liter L Time second s temperature Kelvin K amount of substance mole mol electric current ampere A luminous intensity candela cd

Measurements Conversion factors Significant figures Density Metric (SI) units Prefixes Uncertainty Length Mass Volume Conversion factors Significant figures Density Problem solving with conversion 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

Measurements Conversion factors Significant figures Density Metric (SI) units Prefixes Uncertainty Length Mass Volume Conversion factors Significant figures Density Problem solving with conversion factors

Prefixes You 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

Measurements Conversion factors Significant figures Density Metric (SI) units Prefixes Uncertainty Length Mass Volume Conversion factors Significant figures Density Problem solving with conversion 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 Factor Label Method (used in all chemistry and physics classes. Save yourself lots of grief and learn it now!) Remember these two ideas: Any number can be multiplied by 1 without changing its value. Multiplying by a conversion factor is like multiplying by 1 because the numerator and the denominator are equal. Ex.

Let’s do some together! Ms. B’s college ring weighs ______ g. How many kg is this? Convert 2 L of Monster to mL. 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 tuz 4 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)