1. Introduction to Physical Science Monday, Wednesday, Thursday Tom Burbine tomburbine@astro.umass.edu

2. 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

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

6. 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

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

9. http://www.chemicalelements.com/

10. http://www.periodicvideos.com/

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

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

14. 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

16. 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

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

21. Any Questions?