Do NowDo Now If you baked goodies for today, If you baked goodies for today,

please turn in your paper and open please turn in your paper and open you treats on table #7you treats on table #7

Everybody else, please help yourself Everybody else, please help yourself to some delicious snacks from the to some delicious snacks from the back of the room at table #7back of the room at table #7

When you return to your seat please When you return to your seat please take out your HWtake out your HW

National Mole National Mole DayDay

Celebrating the Celebrating the MolenniumMolennium

The Biology of a MoleThe Biology of a MoleKingdom: AnimaliaKingdom: AnimaliaPhylum: ChordataPhylum: ChordataClass: MammaliaClass: MammaliaOrder: InsectivoraOrder: InsectivoraFamily: TalpidaeFamily: Talpidae

Wrong kind of Wrong kind of

Mole !!Mole !!

In Chemistry a In Chemistry a Mole is a Mole is a UnitUnitIt is an SI unit

symbolizing an amount of matter

The NumberThe Number We have words in We have words in

English that English that signify a certain signify a certain number of itemsnumber of items Couple : twoCouple : two Dozen : twelveDozen : twelve Baker’s dozen : 13Baker’s dozen : 13 Gross : 144Gross : 144

The NumberThe Number A mole also A mole also

represents a represents a certain number of certain number of thingsthings

A mole represents A mole represents 6.022 x 106.022 x 102323 thingsthings

6.022 x 106.022 x 102323

The NumberThe Number That’s a 6 That’s a 6

followed by 23 followed by 23 zeros ! ! !zeros ! ! !

That is truly a That is truly a mindboggling mindboggling number.number.

Just how big is it? Just how big is it? Glad you asked.Glad you asked.

A little number crunchingA little number crunching A person who lives A person who lives

seventy years lives seventy years lives 2.2 x 102.2 x 1099 seconds, seconds, about 2 billion about 2 billion seconds. If this seconds. If this person could count person could count to a billion during to a billion during each second of his each second of his life he could still life he could still not count this highnot count this high

More number crunchingMore number crunching If each of the six If each of the six

billion people on billion people on the face of the the face of the earth were given earth were given 100 trillion dollars 100 trillion dollars each, the sum total each, the sum total of all the money of all the money would equal one would equal one mole of dollars.mole of dollars.

More number crunchingMore number crunching If you were to cover If you were to cover

the state of Texas in the state of Texas in quarters, and then quarters, and then stacked quarter upon stacked quarter upon quarter, you would quarter, you would have to make enough have to make enough layers of quarters layers of quarters covering Texas to covering Texas to measure over 400 measure over 400 miles high before you miles high before you would have one mole would have one mole of quarters.of quarters.

Why would anyone ever Why would anyone ever need a number this big?need a number this big?

Glad you ask

ed

A little backgroundA little background The need for the The need for the

number comes number comes from an attempt to from an attempt to make a connection make a connection between the between the smallest particle of smallest particle of a substance and a a substance and a measurable measurable amount in a lab.amount in a lab.

Atomic massesAtomic masses Atomic masses listed on a periodic table Atomic masses listed on a periodic table

are given in units called are given in units called atomic mass unitsatomic mass units.. Unfortunately, these units are very tiny, Unfortunately, these units are very tiny,

and are very nearly impossible to measure and are very nearly impossible to measure in the lab.in the lab.

An Italian scientist discovered a way to An Italian scientist discovered a way to show that a certain number of atoms of any show that a certain number of atoms of any certain substance had a mass of the same certain substance had a mass of the same number in grams as the atomic mass was number in grams as the atomic mass was in atomic mass unitsin atomic mass units

A mole of a substanceA mole of a substance

One carbon atomHas an atomic massOf 12.0 atomic mass units

Using the same number, 12.0, but changing the unit to grams represents one mole of carbon

6.022 x 10 23one mole of atoms

The discovererThe discoverer Amedeo AvogadroAmedeo Avogadro

was the Italian was the Italian scientist that scientist that calculated the number calculated the number that equals one mole. that equals one mole. For that reason the For that reason the number itself is number itself is named after him.named after him.

Avogadro’s Number, Avogadro’s Number, NNAA, is the basis for the , is the basis for the molemole

This guy kind of looks like a mole!

So, what’s the clincher?So, what’s the clincher?The mole allows us to calculate the

number of atoms in a certain number of grams. Since grams of a substance are easily measured in a lab, we now

have a way to find out how many atoms are in a laboratory sized sample

of material. !