1. Pick up your science journal. This week’s feedback distributer.
Atomic Theory
Pick up your science journal.
This week’s feedback distributer.

2. Rutherford’s Gold Foil Experiment Deflection of beam’s particles (1899)
Box contains redioactive polonium
Some passed straight through, beam’s particles deflected

3. Scanning Tunneling Microscope (1981)
Sharp probe which conducts electricity
When the probe hits an atom, the flow of electrons between the atom and the probe changes

4. Create a timeline Create a timeline which illustrates the following:
John Dalton, J.J. Thomson, Ernest Rutherford, Niels Bohr and two other scientists of your choice!
The dates they introduced their development
A brief description of the development for each person
A drawing of each model
References:
Look at pages 61 – 65 of textbook
Keep track of all the sources that you use! I will request a citation on your poster.

5. EQ: What is the fundamental basis of matter?
Atomic theory
EQ: What is the fundamental basis of matter?
TODAY:
Check back to your beginning of the year goal: Are you meeting your goal? Why or why not?
Hold onto your lab report
This week’s feedback distributer: Paula & Shahrouz
ANNOUCEMENT:
Redo opportunities – quiz, myths
Google drive submission – myths, lab

6. To do today
Complete a self assessment of your lab report. Submit with your lab attached.
Finish atomic theory timeline
Begin isotopes mini research
Your grade thus far – mini meeting

7. Early ideas about matter
About 2500 years ago, Greek philosophers though that air, earth, fire and water were elements that formed all matter
Was matter endlessly divisible or indivisible?

8. John Dalton (1803) All matter is made up of atoms.
Atoms are indestructible and cannot be divided into smaller particles.
All atoms of one element are exactly alike but they are different from atoms of other elements
Evidence: Elements combine in the same percent by mass every time the same compound is formed

9. JJ Thompson (1897)
Atoms composed of subatomic particles that are negatively charged
Plum pudding model: electrons in a ball of positive charge

10. JJ Thompson Evidence: Cathode ray
Vacuum tube, electrode (metal piece), high voltage
When electrodes are charged, rays travel from the negative electrode (cathode) to the positive (anode). Therefore, known as cathode rays.
Apply electric field: Rays bent toward positively charged plate
Cathode rays made up of electrons

11. Ernest Rutherford (1909)
Small densely charged particle called the nucleus
Evidence
Lead shielded box containing radioactive polonium, which emits fast-moving positively charged particles
Gold foil surrounded by screen
Observations: when beam struck the gold foil, some particles passed through while others deflected