dr. joseph w. howard ©2008 science & the physical world when you look around the room, what do...

Dr. Joseph W. Howard

©2008

Science & the Physical WorldScience & the Physical World

When you look around the room, what do you see?

When you look around the room, what do you see?

Can we “categorize” anything?Can we “categorize” anything?

Can we relate seemingly different things?Can we relate seemingly different things?

What does everything in the room have in common?

What does everything in the room have in common?


©2008

Scale Up!Scale Up!

RoomRoom BuildingBuilding CampusCampusCityCity

UniverseUniverse

Scale Down!Scale Down!RoomRoom

PeoplePeopleChairChair

DustDustChalkChalk

AtomAtom


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Scales in ScienceScales in Science• We can explore three scales

Macroscale • Objects the human eye can easily “see” with the

naked eye. [[~millimeter bigger]]Microscale

• Objects you need a “microscope” to “see.” [[~0.000001m 0.001m]]

Nanoscale• Very tiny – nearly impossible to “see” using very

fancy scientific equipment. [[~0.000000001m smaller]]

• Which scale is the most responsible for everything that occurs in the physical world?– Microscopic and macroscopic behavior

determined by objects at the nanoscale level

• We can explore three scalesMacroscale

• Objects the human eye can easily “see” with the naked eye. [[~millimeter bigger]]

Microscale• Objects you need a “microscope” to “see.”

[[~0.000001m 0.001m]]Nanoscale

• Very tiny – nearly impossible to “see” using very fancy scientific equipment. [[~0.000000001m smaller]]

• Which scale is the most responsible for everything that occurs in the physical world?– Microscopic and macroscopic behavior

determined by objects at the nanoscale level


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Closer Look at the NanoscaleCloser Look at the Nanoscale

• Consider a piece of ice from our macroscopic view

• Consider a piece of ice from our macroscopic view


©2008

Closer Look at the NanoscaleCloser Look at the Nanoscale

This is a tiny piece from the block of ice

This is a tiny piece from the block of ice

Consider ice from a nanoscale viewConsider ice from a nanoscale view


©2008

Looking at the Nanoscale: Looking at the Nanoscale:

Divide block of ice in halfDivide block of ice in half


©2008

Looking at the Nanoscale: Looking at the Nanoscale:

• If divided over and over, eventually reach smallest particle that is a particle of ice

• the water molecule

• If divided over and over, eventually reach smallest particle that is a particle of ice

• the water molecule


©2008

NanoScale StuffNanoScale Stuff

Chemical compoundsChemical compounds

atomsatoms

moleculesmolecules

particlesparticles

Periodic tablePeriodic table

protonsprotons

electronselectrons


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• Molecules are composed of atoms• Some substances have atoms, but

not molecules as their fundamental particle

• Elements– substances that consist of only one type

of atom– Mercury for example

• Molecules are composed of atoms• Some substances have atoms, but

not molecules as their fundamental particle

• Elements– substances that consist of only one type

of atom– Mercury for example

Looking at the Nanoscale: The Fundamental Particle



©2008



• Compounds– molecule is fundamental particle– two or more different types of atoms

chemically bound together in the molecule

– ice for example

• Compounds– molecule is fundamental particle– two or more different types of atoms

chemically bound together in the molecule

– ice for example


©2008



• Pure substances and mixtures– mixtures have more than one type of

fundamental particle present

• All substances are made of atoms, but the atom is not necessarily the fundamental particle of the substance

• Pure substances and mixtures– mixtures have more than one type of

fundamental particle present

• All substances are made of atoms, but the atom is not necessarily the fundamental particle of the substance


©2008

How Big is an Atom?How Big is an Atom?

• Typically about 0.0000000001 m long

• 1 atom of Cu weighs0.000000000000000000000000233 lb

• Typically about 0.0000000001 m long

• 1 atom of Cu weighs0.000000000000000000000000233 lb

In Scientific Notation, • 0.0000000001 m is 1 x 10-10 m • 0.000000000000000000000000233 lb

is 2.33 x 10-25 lb

In Scientific Notation, • 0.0000000001 m is 1 x 10-10 m • 0.000000000000000000000000233 lb

is 2.33 x 10-25 lb


©2008

Scientific NotationScientific Notation

1 hectogram = 1102 grams = 11010 = 100 grams

5,100,000 fish = 5.11,000,000 = 5.1101010101010 fish= 5.1106 = 5.1 mega-fish

1.23 picoseconds = 1.2310-12 seconds

= 0.00000000000123 seconds


©2008

Changing UnitsChanging Units

Often you will need to change one unit to another unit.

How many quarters are in $5? (US)

You actually do this every day!

Unit Conversion (Keep track of the factor labels)

5 dollars

dollar 1

quarters 4= 20 quarters [ I multiplied! ]

60 eggs

eggs 12

dozen 1= 5 dozen [ I divided! ]

How many dozen are in 60 eggs?


©2008

ExampleExample

How many seconds are in 1 earth day?

day 1

hours 241 day

hour 1

min 60

min 1

seconds 60= 86,400 secs

8.64104 seconds


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cents 100

dollar 1

ExampleExample

Being a young entrepreneur you go into business operating a “kissing booth” at the local carnival and charge 50¢ for every kiss. How many dollars do you make if you sell 2.3 kilokisses?

2.3 kilokisses = 2.3103 kisses = 2.31000 kisses= 2300 kisses

2300 kisses

kiss 1

cents 50= $ 1150


©2008

1x10-15 m 1x10-15 m one fermi

1 fm 1x10-15 m diameter of proton (in the nucleus)

2.2 fm 2.2x10-15 m classical diameter of neutron

3.8 fm 3.8x10-15 m diameter of the nucleus of a helium atom

5.635882 fm 5.635882x10-15 m classical diameter of an electron

7.2 fm 7.2x10-15 mdiameter of the nucleus of an aluminum atom

14 fm 1.4x10-14 m diameter of the nucleus of a gold atom

How small is small?How small is small?


©2008

2 mm 2x10-3 m diameter of a large grain of sand

2 mm 2x10-3 m size of a small ant

4.234 mm 4.234x10-3 m height of a line of text in 12-point type

10 mm 1x10-2 m one centimeter

1.7 cm 1.7x10-2 m wavelength of 20khz note (highest that can be heard) at 27 degrees celsius

2.5 cm 2.5x10-2 m size of a large ant

2.54 cm 2.540x10-2 m one inch

8.5 cm 8.5x10-2 m length of largest human chromosome if it were stretched end-to-end

12.2 cm 1.22x10-1 m wavelength of microwaves in a microwave oven

30 cm 3.0x10-1 m one foot

79 cm 7.9x10-1 m wavelength of 440 hertz note (A above middle C) at 27 degrees celsius

91 cm 9.1x10-1 m one yard

1 m 1 m one meter



©2008

Pluck a hair from your head.

Examine that single strand of human hair. Now imagine slicing that hair lengthwise into 10 strips. Each piece would be too small to see with the naked eye and would be about as wide as a typical human cell, about 5 millionths of a meter.

Now cut one of those slices 10 more times, and you've reached the limit of vision of the best optical microscopes. But now comes the big step. Take one of these strips and cut it 1,000 more times. The resulting pieces now contain only a few atoms -- and you've entered the nanoscale realm.

• This means there are about 105 atoms across the width of a human hair.•The same number of hairs (105) put side by side would be 5 meters in length.• The average human head has 105 hairs. (Looked it up)• 105 meters is 62.2 miles

Pluck a hair from your head.

Examine that single strand of human hair. Now imagine slicing that hair lengthwise into 10 strips. Each piece would be too small to see with the naked eye and would be about as wide as a typical human cell, about 5 millionths of a meter.

Now cut one of those slices 10 more times, and you've reached the limit of vision of the best optical microscopes. But now comes the big step. Take one of these strips and cut it 1,000 more times. The resulting pieces now contain only a few atoms -- and you've entered the nanoscale realm.

• This means there are about 105 atoms across the width of a human hair.•The same number of hairs (105) put side by side would be 5 meters in length.• The average human head has 105 hairs. (Looked it up)• 105 meters is 62.2 miles


dr. joseph w. howard ©2008 science & the physical world when you look around the room, what do...

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