1. Early periodic tables Dobereiner - early 1800s Triads- elements with similar properties Cl, Br, I Ca, Sr, Ba Newlands - 1865 62 known elements Law of Octaves (every 8 th element is similar)

2. Mendeleev’s table - 1869 By atomic mass In columns Predicted missing elements

3. Moseley’s table – 1910’s Working in Rutherford’s lab Arranged by positive charge he called atomic number In rows Died in WWI

4. Periodic law When the elements are arranged by increasing atomic number, their physical and chemical properties show a repeating pattern

5. ELEMENTS Metals left side of periodic table Nonmetals right side of periodic table Metalloids along diagonal line

6. Metals Lose electrons to make + ions (cations) Conduct electricity Conduct heat Malleable Ductile React with acids Solids (except ?) Shiny

7. Nonmetals Gain electrons to form – ions (anions) Do not conduct heat Do not conduct electricity Brittle Solids, liquids or gases Do not react with acids Dull

8. Metalloids Properties of either Some gain, some lose electrons Some conduct, some don’t Some are malleable, some brittle All are solids

9. Patterns of Atomic Numbers A-6 Family NameIonValence electron Alkali metals (H) +1 1 Alkaline earth(Be) +2 2 Aluminum (B) +3 3 Carbon+/-44 Nitrogen-35 Oxygen-26 Halogen(F)-17 Noble(He)08

10. Trends Atomic radiusAtomic radius Melting pointMelting point ElectronegativityElectronegativity Oxidation number (charge on ion)Oxidation number (charge on ion)

11. Atomic radius Size of the atom Down a family atoms get bigger due to more energy levels Across a periodAcross a period atoms get smaller due to more pull by protons on electrons

12. 1. Which is bigger Be or O? Why? Be 2.Which is bigger Li or K? Why? K 3.Which is smaller B or Al? Why? B 4. Which is smaller F or Cl? Why? F

13. Atomic Size Li Na K Rb Cs H Ne Ar Kr Xe Rn

14. Electronegativity the desire of an atom to steal another atoms electron Down a familyDown a family electronegativity get smaller Across a periodAcross a period electronegativity gets larger

15. Electronegativity F Cl Br I He Ne Ar Kr Xe

16. Oxidation Number Charge on the ion Metals Lose electrons – get smaller +1, +2, +3, +4 Non metals - get bigger gain electrons -3, -2, -1 -3, -2, -1

17. Oxidation Number C Si CaSrBa N P Se I

18. Melting Point Down a familyDown a family melting point gets smaller Across a periodAcross a period melting point gets larger

19. Melting Point C Si Ca SrBa HeNe Ar Kr Xe

20. What determines properties A - 7 Ionic Compounds Metal/nonmetal steal electrons +/- attraction strong High melting/boiling points Molecules Nonmetal/nonmetal share electrons Weak attraction Low melting/boiling points

21. Periodic table A-4 Mendeleev 1869 Organized elements by increasing atomic mass (weight) in columns Predicted missing elements Today’s table Organized by increasing atomic number (protons) in rows

22. 1.Which has a smaller melting point N or P? P 2.Which has a smaller melting point Na or Mg? Mg 3.If the melting point of Si is o C and S is o C what would you expect the melting point of P to be?

23. Octet Rule An atom will gain or lose electron to have an octet (or filled) valence energy level