Atomic Timeline (AKA The 7 Dead Dudes of Atomic Theory)
Timeline Construction • Use the adding machine tape to make your Atomic Timeline • Make sure you include… • Name • Date • Important Information • Picture/or/Symbol
1) Democritus – 460 BC • First to develop the idea that matter was made of particles called Atoms • The term “Atoms” comes from the Greek word “atomos” which means “undivisible”
2) John Dalton - 1803 • Proposed atomic theory • An atom is indivisible, indestructible, tiny sphere. • Determined that elements have unique atomic masses
3) Joseph John Thomson - 1898 • Discovered Electrons • Proposed an atomic model known as the “plum pudding” model
4) Ernest Rutherford - 1911 • Discovered positively charged nucleus by probing atoms of gold foil with positively charged particles. • Proposed atomic model with massive nucleus with electrons in a circle around it in a solar system model
5) Niels Bohr - 1913 • Developed atomic model that placed electrons in specific energy levels to explain why they did not spiral toward and collide with the nucleus • Proposed the model with electrons in specific orbits around the nucleus
6) James Chadwick - 1932 • Discovered neutron as a neutral particle in the nucleus • The discovery explained why the mass of an atom could not be attributed entirely to the mass of the protons (+) Positive Protons (0) Neutral Neutrons Nucleus
7) Erwin Schrodinger – 1933 • Described electrons as waves with their probable location viewed as a cloud and introduced a mathematical model of the atom e-
Way to Remember the Order of the Scientists for the Atomic Theory… • Democritus Democritus • Discovered Dalton • Tiny Thomson • Round Rutherford • Circular Chadwick • Ball-like Bohr • Spheres Schrodinger
Scenario The Phantom wants to create life sized models of atoms, and he wants your help! Help the Phantom investigate the world of the very small by cutting a 28 centimeter strip of paper in half as many times as you can. If you can cut the strip of paper in half 31 times you will end up with a piece of paper the size of an atom.
Materials • 1 strip of paper 28 centimeters long (11" inches) • 1 pair of scissors • Patience • Good Eye
Directions • Take your strip of paper and cut it into equal halves. • Cut one of the remaining pieces of paper into equal halves. • Continue to cut the strip into equal halves as many times as you can. • Make all cuts parallel to the first one. When the width gets longer than the length, you may cut off the excess, but that does not count as a cut.
How far did you get? Here are some comparisons to think about! • Cut 1- 14.0 cm5.5"Child's hand, pockets • Cut 2- 7.0 cm2.75"Fingers, ears, toes • Cut 3- 3.5 cm1.38"Watch, mushroom, eye • Cut 4- 1.75 cm.69"Keyboard keys, rings, insects • Cut 6- .44 cm.17"Poppy seeds • Cut 8- 1 mm.04"Thread. • Congratulations if your still in!
Comparisons (con’t) • Cut 10- .25 mm.01“Still cutting? Most have quit by now • Cut 12- .06 mm.002"Microscopic range, human hair • Cut 14- .015 mm.006"Width of paper, microchip components • Cut 18- 1 micron.0004"Water purification openings, bacteria • Cut 19- .5 micron.000018"Visible light waves • Cut 24- .015 micron.0000006"Electron microscope range, membranes • Cut 31- .0001 micron.0000000045"The size of an Atom!
Summary • Is there anything smaller? Yes, the size of an atom nucleus would take about 41 cuts! Scientists use advanced technology to explore the world of electrons and quarks that are at least 9,000 times smaller than a nucleus. • We can not see anything smaller than an atom with our eyes, even with the electron microscope. Physicists study much smaller things without seeing them directly. • Is there an end to the quest for the smallest and most basic elements in our world? The search began with the Greeks and continues as scientists search for the Building Blocks of the universe. These things are far beyond the range of sensory perception but not beyond the range of human understanding.
Size of Atoms • Tiny! • Tinier than the cells and germs. • Too small to be seen with ordinary microscopes • Atoms are so small that it would take 100 million atoms placed side by side to form a row only 1 cm long which is about the width of your pinky finger!
How Small is the Small Stuff? • Let’s check it out… • http://www.micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10 • http://www.cellsalive.com/howbig.htm • http://www.strangematterexhibit.com/structure.html • http://learn.genetics.utah.edu/content/begin/cells/scale/ • http://www.azonano.com/Details.asp?ArticleID=1780
What’s the Matter? Matter
What’s the Matter? “Stuff” that Everything is made of! Made of Atoms Matter Has Volume= Takes Up Space Has Mass= The Amount of Matter in an Object
What was the “Small Stuff” anyway? • Atoms • Elements • Molecules • Compounds
Atoms • Basic unit of matter • The smallest particle of a substance that has all of the properties of that substance. • Example= the element Gold is made of gold atoms
Elements • A pure substance made of only one kind of atom. • Examples= Gold, Hydrogen, Carbon, etc. • Elements are found on the Periodic Table of Elements. • Here is a song about them… http://www.privatehand.com/flash/elements.html
Molecules • Made up of two or more atoms joined tightly together. • Small particle of the entire substance or compound • Atoms in a molecule may be of the same element or of different elements. • Examples= 1 molecule of the element oxygen or 1 molecule of the compound water H2O
Compounds • A substance whose molecules contain atoms of different elements combined chemically. • Most matter exists as compounds. • Examples= Water, Carbon Dioxide, etc.
What is the difference between a Compound and a Molecule? • A molecule is formed when two or more atoms join together chemically. • Molecules can be made up of atoms joined together or elements joined together which form compounds • A compound is a molecule that contains at least two different elements.
Compound vs. Molecule • All compounds are molecules but not all molecules are compounds! • Molecules that are made of two atoms joined together are not compounds • Compound = entire substance • Molecule = small particle of entire substance
Atom • Smallest part of a substance • Has all of the properties of that substance • Compound • Molecules • containing • atoms • of different • elements • Element • Pure Substance • Made of 1 kind • of atom • Molecule • 2 or more atoms • joined tightly • together • Smallest part • of compound
Atom • Smallest part of a substance • Has all of the properties of that substance
Element • Pure Substance • Made of 1 kind of atom
Molecule • 2 or more atoms • joined tightly • together • Smallest part • of compound
Compound • Molecules containing atoms of different elements
Chemical Bonding • Elements bond together to form compounds • 2 Main Types of Bonding… • Colvalent = sharing of e- • Ionic = giving or taking of e-
Covalent Bonding = Sharing e- • Covalent Bond= sharing of electrons that occurs between 2 non-metals Ex) Water H2O H H O = Hydrogen’s Electron = Oxygen’s Electrons
Ionic Bonding = give or take e- Ionic Bond= giving or taking of electrons that occurs between metals and non-metals Ex) Salt NaCl – Na give outer e- to Cl Na Cl Na1+ Cl1-
Ions • An ion is an atom or molecule which has lost or gained one or more electrons, making it positively or negatively charged. • A negatively charged ion, which has more electrons in its electron shells than it has protons in its nuclei, is known as an anion • Conversely, a positively-charged ion, which has fewer electrons than protons, is known as a cation
Ions (con’t) • An ion consisting of a single atom is called a monatomic ion, but if it consists of two or more atoms, it is a polyatomic ion. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions. • Ions are represented by the presence of a superscript indicating the sign of the net electric charge and the number of electrons lost or gained, if more than one. For example: H+ and SO42−.
Elements in the Earth & Air ElementSymbol Use • Oxygen O Breathing • Silicon Si Glass/Rocks • Aluminum Al Foil/Cans • Iron Fe Steel • Calcium Ca Bones/Teeth • Potassium K Bones/Muscles • Sodium Na Salt
Elements In Our Bodies Ca 1.6% N 2.4% Other 3.3% H 10.2% O 65% C 17.5%
The Atoms Family Welcome to Matterville!
Welcome to Matterville (where everything matters!) In the center of Matterville, there is a place called the Nucleus Arcade, where two members of the Atoms Family like to hang out. Perky Patty Proton, like her sisters, is quite large with a huge smile and eyes that sparkle (+). Patty is always happy and has a very positive personality. Nerdy Nelda Neutron is large like Patty, but she has a boring, flat mouth and eyes with zero expression (o). Her family is very apathetic and neutral about everything. Patty, Nelda, and their sisters spend all their time at the arcade.
Around the Nucleus Arcade, you will find a series of roadways that are used by another member of the Atoms Family, Enraged Elliott Electron. Elliott races madly around the Arcade on his bright red chrome-plated Harley-Davidson. He rides so fast that no one can be sure where he is at any time. Elliott is much smaller than Patty and Nelda and he is always angry because these bigger relatives will not let him in the Arcade. He has a frown on his face, eyes that are squinted with anger, and a very negative (-) attitude.
The first energy street can only hold only two Electron brothers. The second energy street, called the Energy Freeway, can hold 8 brothers. The third energy street, called the Energy Superhighway, can hold 18 of the brothers.
The morale of Matterville is stable as long as each negative Electron brother is balanced out by one positive Proton sister. The number of residents in Matterville depends on the Proton and Neutron families. Challenge: What would happen to the morale of Matterville if one Elliott Electron was kidnapped?
Morale of Matterville The morale of Matterville is stable as long as it has the same number of protons (+) and electrons (-). If someone kidnaps one Elliott Electron, the morale of Matterville would become positive (more protons). If one Elliott Electron were to move to Matterville, the morale would be negative (more electrons).