2. Definitions What is matter? Anything that takes up space and has mass What is mass? Measure of the number of atoms in an object

3. What is an element? A single type of atom – defined by its number of protons What is a compound? Two or more elements chemically combined What is a molecule? The smallest unit of a compound

4. Structure of the Atom Nucleus – central part of an atom (contains Protons(+) and Neutrons(0) Orbitals or Electron Cloud – area where electrons orbit the nucleus (contains Electrons(-))

5. The Periodic Table of Elements First created by DIMITRI MENDELEEV

6. Periodic Table PERIODS (or rows) G R O (or columns) U P SElements are arranged with similar properties!

7. SYMBOL Atomic Mass # Atomic #

8. Atomic Number = an atoms # of Protons The # of Protons = # of electrons in a stable atom Atomic Mass Number = an atoms # of protons +# of neutrons Atomic Mass Units – 1/12 the mass of a carbon atom

9. SYMBOL Atomic Mass # Atomic # = # of Protons = # of electrons Protons, Neutrons, and Electrons ATOMIC MASS – ATOMIC # = Neutrons (4-2) = 2

10. Practice Group # = Period # = Atomic # = Mass # = # of protons = # of neutrons = # of electrons =

11. Exit Questions 1. Group # = 2. Period # = 3. Atomic # = 4. Mass # = 5. # or P + = 6. # of E - = 7. # of N o =

12. BOHR MODEL of the atom Chlorine Atomic # 17 Mass # 35 17 protons 17 electrons 18 neutrons

13. Electron Shells 2 8 18 36

14. Valence Electrons Valence Electron – an electron in the outermost electron shell

15. Draw a simple Bohr model for… Hydrogen Lithium Sodium How many valence electrons do they have?

16. Dot Diagrams

17. Properties of Elements Metals – Left of the ladder Good conductors, malleable, ductile, solid Non-metals – Right of the ladder Poor conductors, brittle, most are gasses Metalloids – On the ladder Share properties of both metals and non-metals

18. Is it a metal or a non-metal? Sodiummetal or non-metal Carbonmetal or non-metal Nitrogenmetal or non-metal Lithiummetal or non-metal Goldmetal or non-metal Oxygenmetal or non-metal Magnesiummetal or non-metal Fluorinemetal or non-metal

19. Stable electron configuration Atoms with a complete (filled) outermost electron orbital 8 electrons = complete, stable electron orbital All the noble gasses have a stable electron configuration

20. Bonding Ionic Bond – Attractive force between a positively charged particle(+) and a negatively charged particle(-) – transfer of electrons – between a metal and a non-metal Covalent Bond – Sharing of electrons between two non-metals

21. Electron Lenders and Borrowers METALS – lenders (less than 4 valence electrons) NON-METALS – borrowers (more than 4 valence electrons) Metal - Sodium (1 valence electrons) – lends 1 electron becomes +1… in order to become stable like the noble gasses Non-Metal – Flourine (7 valence electrons) – borrows 1 electron becomes -1… in order to become stable like the noble gasses

22. Is it an Ionic or Covalent Bond? Magnesium Sulfide IonicCovalent Carbon DioxideIonicCovalent Nitrogen DioxideIonicCovalent Lithium BromideIonicCovalent Sulfur DioxideIonicCovalent Barium OxideIonicCovalent Iron SulfideIonicCovalent

23. Ionic Bonds - Review TRANSFER OF ELECTRONS METALS x Non-METALS Metals lend electrons (less than 4) Non-Metals borrow electrons (more than 4)

24. Drawing the Ionic Bonds Magnesium Chloride (MgCl 2 )

25. Covalent Bonds - 8 SHARING OF ELECTRONS Non-METALS x Non-METALS

26. Drawing the Covalent Bonds Water(H 2 O)