1. What is Matter? Matter is anything that has mass. All objects are made of matter. Air, water, a brick, even you are made of matter!

2. States of matter

3. VIDEO-Clip: http://www.britannica.com/EBchecked/topic/41549/atomhttp://www.britannica.com/EBchecked/topic/41549/atom Atomic particles and isotopes

4. Particles smaller than an atom. They may be elementary or composite. Electrons (elementary) Protons (composite), made of 3 quarks Neutrons (composite), made of 3 quarks Subatomic particles

5. Over eighty years ago, scientists thought that the atom was the smallest piece of matter. Atom: the building block of matter John DALTON (1844) Solid sphere model John DALTON http://www.etownschools.org/Page/3502

6. John DALTON’s atomic theory VIDEO CLIP: http://www.britannica.com/EBchecked/topic/41549/atomhttp://www.britannica.com/EBchecked/topic/41549/atom

7. 1940 John Thomson 1906 Nobel Prize in Physics John THOMSON discovered the electrons John THOMSON discovered the electrons

8. The Cavendish Laboratory, Cambridge (UK) Thomson at work

9. A simple cathode ray tube. What could these rays be? What could these rays be? VIDEO (3:46’) http://www.youtube.com/watch?v=4QAzu6fe8rEhttp://www.youtube.com/watch?v=4QAzu6fe8rE

10. He advanced the idea that cathode rays are really streams of very small pieces of atoms. Do atoms have parts? JJ Thomson suggested that they do! J.J. Thomson experimenting "We have in the cathode rays matter in a new state."

11. J.J. Thomson Talks About the Size of the Electron To listen to J.J. Thomson speaking on his discovery: Recording made in 1934. From the soundtrack of the film, Atomic Physics copyright © J. Arthur Rank Organization, Ltd., 1948. "Could anything at first sight seem more impractical than a body (the electron) which is so small that its mass is an insignificant fraction of the mass of an atom of hydrogen? --which itself is so small that a crowd of these atoms equal in number to the population of the whole world would be too small to have been detected by any means then known to science." AUDIO: http://www.aip.org/history/electron/jjsound.htmhttp://www.aip.org/history/electron/jjsound.htm

12. Raisin cake model John THOMSON’s model of the atom J.J. Thomson theorized that electrons were surrounded by a positively charged material, uniformly distributed.

13. Ernest Rutherford discovered the nucleus 1937 Ernest Rutherford Nobel Prize Solar system model 1908

14. Rutherford’s experiment The gold-foil experiment VIDEO: http://www.youtube.com/watch?v=Zd6_zVdMgJkhttp://www.youtube.com/watch?v=Zd6_zVdMgJk Alpha particle: helium nucleus (4u 2+ )

15. Expected results according to….. Thomson’s model Rutherford’s model

16. Rutherford envisioned the atom as a miniature solar system, with electrons orbiting around a massive nucleus. Rutherford’s model of the atom Solar system model

17. What is Matter?

18. neutrons

19. mesons

20. Quarks and gluons

21. Do you think that the quark is the smallest piece of matter or do you think that there might be something smaller inside the quark?

22. You name it!

24. The model of atom created by Rutherford Rutherford shouldn’t exist! According to classical physics, an electron in orbit around an atomic nucleus should emit electromagnetic radiation (photons) continuously. The resulting loss of energy implies that the electron should spiral into the nucleus in a very short time (atoms cannot exist!!)

25. Quantized shell model 1962 Niels BOHR 1922 Nobel Prize Niels BOHR

26. In 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. quantized shell model Bohr proposed that electrons are restricted to certain fixed (quantized) orbits. An electron can jump between these orbits by absorbing or emitting a photon with the appropriate precise wavelenght. Fixed orbits

27. Bohr's idea was that each discrete orbit could only hold a certain number of electrons. After that orbit is full, the next level would have to be used. This gives the atom a shell structure, in which each shell corresponds to a Bohr orbitshell structure Shell model of the atom VIDEO: http://www.britannica.com/EBchecked/topic/41549/atom/48360/Bohrs- shell-model

28. For working hard with me!

29. VIDEO: http://www.britannica.com/EBchecked/topic/41549/atom/48360/Bohrs- shell-model Electronic configuration of different atoms

30. VIDEO: http://www.britannica.com/EBchecked/topic/41549/atom/48360/Bohrs- shell-model Nuclear fission

31. VIDEO: http://www.britannica.com/EBchecked/topic/41549/atom/48360/Bohrs- shell-model Atomic bonds

32. VIDEO: http://www.britannica.com/EBchecked/topic/41549/atom/48360/Bohrs- shell-model Nuclear power