1. Science Review for Alana

2. What’s an atom? Smallest unit of matter

3. Structure of an atom Electron Cloud Nucleus

4. Subatomic Particles In the Nucleus: In the Electron Cloud: Protons: + charge Neutrons: no charge Mass of each:1 atomic mass unit (amu) Electrons: - charge Practically no mass

5. Neutral atom

6. Check What are the two overall structures in the atom? What are the names of the atomic particles?

7. What’s an element? Atoms with different numbers of protons

8. Atomic Number # of protons=atomic number Identification (student id# or SSN)

9. Why is it called “periodic”?

10. Check Where are the protons located? Where are the electrons located? Where are the neutrons located?

11. Neutral atom

12. Mass Number Protons + Neutrons

13. Exercise Draw a neutral lithium atom (protons, neutrons, electrons) with an mass number of 7

14. Isotope Atom with same # of protons but different # of neutrons (different mass number)

15. Radioactivity Too many or too few neutrons compared to protons UNSTABLE It wants to be sane (more stable)…so it gets rid of something! Emits a particle or energy Ever heard of uranium? Types of nucleus radiation that can be emitted: Alpha Beta Gamma

16. Check What is the atomic number?

17. Atomic mass Weighted atomic mass of the isotope of an element

18. Structure of an atom Electron Cloud Nucleus

19. Electron cloud Electrons arranged in Energy level 1st level can hold 2 electrons 2nd energy level can hold 8 3rd…18 4th…32 Outermost electrons called valence electrons – chemical bonds

20. Electron cloud

21. Exercise Draw a neutral carbon atom with an atomic mass of 12 Draw the electron cloud of Na Draw the electron cloud of Cl

22. Bonding As it turns out, atoms bond together for a very simple reason: atoms like to have full valence shells http://web.jjay.cuny.edu/~acarpi/NSC/5-bonds.htm http://www.kentchemistry.com/links/bonding/bondingflashes/bond_types.swf

24. Ions Atoms that are Not neutral # Electrons not equal to # protons Previous example of sodium and chlorine

26. Part K on review sheet

27. States/Changes of matter Solids, liquids, gases http://www.chem.purdue.edu/gchelp/liquids/character.html http://www.clickandlearn.org/Gr9_Sci/Particle_Theory.htm

28. Solutions http://www.chem4kids.com/files/matter_solution.html