1. Conversations with the Earth Tom Burbine tburbine@framingham.edu

2. Chemistry The science of matter and the changes it undergoes.

3. Atoms Atoms are made up of 3 types of particles Protons – positive charge (+1) Electrons – negative charge (-1) Neutrons – neutral charge (no charge) Protons and Neutrons are found in the nucleus

5. Elements Different elements have different numbers of protons The properties of an atom are a function of the electrical charge of its nucleus

7. Definitions Atomic Number – Number of protons Atomic Mass – Number of protons and neutrons U 235 – atomic mass 92- atomic number Isotopes – Same number of protons but different numbers of neutrons

9. http://www.youtube.com/watch?v=GFIvXVMbII0

10. http://www.chemicalelements.com/

11. http://www.periodicvideos.com/

12. Periodic Table A chart in which all known elements are listed in order of atomic number http://theodoregray.com/periodictable/

13. http://cosmiclog.msnbc.msn.com/_news/2011/01/ 26/5925968-see-the-worlds-smallest-periodic- tablehttp://cosmiclog.msnbc.msn.com/_news/2011/01/ 26/5925968-see-the-worlds-smallest-periodic- table

14. Period – Horizontal row Across any period, the properties of elements change Group – Vertical column Down any group, the properties of elements are very similar

16. Radioactivity Radioactivity – decay of an atomic nucleus All elements with an atomic number greater than 82 (lead) are radioactive

17. Bohr’s Planetary Model Electrons orbit the nucleus in specific energy levels Level n=1 is closest to nucleus Level n=2 is second closest

19. Shell Model Electrons behave as they are arranged in a series of concentric shells around the nucleus Innermost shell can contain 2 electrons The second and third shells can contain 8 electrons each The fourth and fifth shells can contain 18 electrons each

20. Valence electrons are the electrons in the outermost shell These electrons participate in chemical bonding

23. Ion Ion – an electrically charged particle created when an atom either loses or gains one or more electrons

27. Ionic Bond Ionic bond – chemical bond in which an attractive electric force holds an opposite charge together

28. Covalent Bond Covalent bond – a chemical bond in which atoms are held by their mutual attraction for two or more electrons share Molecules are held together by covalent chemical bonds

31. Metallic Bonds Atoms "share" electrons that float about in a general electron cloud

33. Charges need to balance Na ions carry a +1 charge Cl ions carry a -1 charge Na + + Cl - → NaCl (Sodium chloride)

34. HCl – Hydrogen Chloride Li 2 O – Lithium Oxide CO – Carbon Monoxide CO 2 – Carbon Dioxide

36. http://www.hulu.com/watch/63320/cosmos-the- lives-of-the-stars#s-p1-so-i0http://www.hulu.com/watch/63320/cosmos-the- lives-of-the-stars#s-p1-so-i0

37. Any Questions?