Properties of Matter: Physical Properties

Properties of Matter: Physical Properties Cscope Unit 3Lesson 1

1TEKS The student knows that relationships exist between properties of matter and its components. 7B Research and describe the historical development of the atomic theory.

2Key Understandings and Guiding Questions-The development of the atomic theory comes from the contributions of several scientists.

How has atomic theory evolved over time, and why is it not considered a law? -

3Vocabulary of Instructiontheory law atomic theory

4Mystery BoxesGet in groups of 4Get a set of mystery boxes 1-3Do not open or peek inside boxes. Do your best to figure out what is inside each without looking. Write down your conclusion for each box

5How did you come to your conclusions?

What senses did you use? Did you use any tools? [Such as a triple beam balance.] Hand the boxes in, do not open them

6Boxes answers?Im Not telling you the answers CONFUSED?

Scientist dont know the answers they must do there best without all the answers

7A Theory is an explanation of a natural event. Theories are sometimes our best guess, and are often revised as we discover new information.Example; the formation of the Universe

If proven- over time it can become a law.

8Example of a theory- Kinetic TheoryThe KINETIC MOLECULAR THEORY states that molecules are in constant motion.

The molecules are in motion and hit the all side of the balloonEqually, causing it to expand equally

9A law states a summary of a repeated observation about a natural event.

The sun always rises in the East

Scientific Law10Law

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Hot wheels are nearly exact replicas of cars but smaller

They are models of carsthey can help us understand what a type of car looks like

12A MODEL is a replica of an object or event.MODELS MAY BE:drawingsmental picturesa set of rulesphysical objectscomputer picturesIdentify some models in our classroom.Identify some things in the classroom that are NOT models

13Model ActivityGroups of 4Number off 1-4 at each table1- read directions2- locate the next piece3- put the piece in the correct place4- checker to verify correctness

Build the model that is at your table.Follow the directions14ModelsIn the case of atoms, scientists use large models to explain something that is very small

Models of the atom were used to explain data or facts that were gathered experimentally. So, these models are also theories15History of the Atomic Theory16Research projectAtomic Theory Timeline (use your hand out)Create a timeline you have 1 day to research, 1 day to construct itInclude- Scientists who contributed to the atomic theory Significant discoveries New inventions which helped scientists in their studies Draw the atoms at each stage

17Atomic Structure TimelineUse the following information to complete the lecture handout. On tomorrows quiz, you will be expected todraw the atomic modelsmatch scientists to their experiments and discoveriesplace the models in chronological orderDemocritus (400 B.C.)

Proposed that matter was composed of tiny indivisible particles

Not based on experimental data

Greek: atomosAlchemy (next 2000 years)

Mixture of science and mysticism. Lab procedures were developed, but alchemists did not perform controlled experiments like true scientists.John Dalton (1807)

British Schoolteacherbased his theory on others experimental dataBilliard Ball Modelatom is a uniform, solid sphere

John DaltonDaltons Four Postulates1.Elements are composed of small indivisible particles called atoms.2.Atoms of the same element are identical. Atoms of different elements are different.3.Atoms of different elements combine together in simple proportions to create a compound.4.In a chemical reaction, atoms are rearranged, but not changed.Henri Becquerel (1896)

Discovered radioactivityspontaneous emission of radiation from the nucleusThree types:alpha () - positivebeta () - negativegamma () - neutralJ. J. Thomson (1903)

Cathode Ray Tube Experimentsbeam of negative particlesDiscovered Electronsnegative particles within the atomPlum-pudding ModelJ. J. Thomson (1903)Plum-pudding Modelpositive sphere (pudding) with negative electrons (plums) dispersed throughout

Ernest Rutherford (1911)

Gold Foil ExperimentDiscovered the nucleusdense, positive charge in the center of the atomNuclear ModelErnest Rutherford (1911)Nuclear Modeldense, positive nucleus surrounded by negative electrons

Rutherfords gold foil experimenthttp://www.shsu.edu/%7Echm_tgc/sounds/pushmovies/l2ruther.gif - source of animation

28Niels Bohr (1913)

Bright-Line Spectrumtried to explain presence of specific colors in hydrogens spectrumEnergy Levelselectrons can only exist in specific energy statesPlanetary ModelNiels Bohr (1913)Planetary Modelelectrons move in circular orbits within specific energy levels

Bright-line spectrumErwin Schrdinger (1926)Quantum mechanics electrons can only exist in specified energy statesElectron cloud model orbital: region around the nucleus where e- are likely to be found

Erwin Schrdinger (1926)Electron Cloud Model (orbital)dots represent probability of finding an e- not actual electrons

James Chadwick (1932)

Discovered neutronsneutral particles in the nucleus of an atomJoliot-Curie Experimentsbased his theory on their experimental evidenceJames Chadwick (1932)

Neutron Modelrevision of Rutherfords Nuclear Model Current atomic modelElectron Cloud Model- nucleus with protons and neutrons in the centerElectrons in clouds around the nucleus- very large area compared to the nucleusElectrons move too fast to find exact location at any one timeAtoms are mostly empty space!http://www.teachersdomain.org/resource/phy03.sci.phys.matter.atoms/

35Modern Models of AtomsQUARKSProtons, and neutrons are made up of smaller particles- quarksQuarks- smallest particles- make up protons, neutrons, and electrons- 6 typesup, down, top, bottom, strange and charmTo study quarks- accelerate charged particles to high speeds and cause them to collide with protons, breaking the proton

36QUARKShttp://en.wikipedia.org/wiki/Particle_acceleratorA proton is made up of 2 up quarks and 1 down quark = charge of +1a neutron contains 1 up quark and 2 down quarks, yielding a net charge of 0

All youve learned about atomic structure is just a modelModel- help you visualize or understand something too large or small to see all at once http://www.teachersdomain.org/resources/phy03/sci/phys/matter/atoms/index.html 37A closer look at quantum mechanics:http://www.fearofphysics.com/Atom/atom1.html 38Atomic Theory Model the smallest unit of an element, having all the characteristics of that element consisting of a dense, central, positively charged nucleus surrounded by a system of electrons.

But this theory will change again as we gather new information 39JOKEA neutron walks into a restaurant and orders a coke. As she is about to leave, she asks the waiter how much she owes. The waiter replies "For you, No Charge! ,!!"

40Atoms Family Album a Story OF aTOMS41Atoms Family AlbumAround 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.

Elliot Electron42In 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.

Atoms Family Album+ +Patty ProtonNelda Neutron43

Atoms Family AlbumThe 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.

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45Atom worksheetComplete the diagram of the Bohr model of the atom Cut it out glue it into your notebook46Alternate- Poster; AtomA Get in groups of 4 (count off 1-4)Jobs -1 recorder , 2 draw, 3 research, 4 spokes personGet a big sheet of paperMake a poster about atomsDraw and label atom, you have 10 minutesTopic-What do you know/remember about the atom? Spokesperson show poster and tell us about it

47JOKETwo atoms are walking down the street. Says one atom to the other, "Hey! I think I lost an electron!" The other says, "Are you sure??" "Yes, I'm positive!"

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