1. Periodic Table Organizing the Elements

2. Antoine Lavoisier (1790s) French Chemist
About 23 elements Au, Ag, C, O

3. Antoine Lavoisier (1790s)
Electricity allowed compounds to break down into elements
Spectrometer
Industrial Revolution – Petrochemicals, soaps, fertilizers, and dyes.

4. John Newlands ( )
English – Arrange elements in increasing atomic mass order, properties repeated themselves every eighth element
Octet rule

5. John Newlands ( )
Octet rule does not apply to Hydrogen and Helium

6. Lothar Meyer (1830-1895) German Chemist
Relationship between Mass and properties

7. Dmitri Mendeleev ( )
Russian Chemist
About 70 elements

9. Dmitri Mendeleev
Predicted the existence and properties of the missing elements
Left blanks for them on his table.

10. Dmitri Mendeleev
How did he line up the elements?

11. Dmitri Mendeleev How did he line up the elements?
Increasing atomic mass
Similar properties side by side

12. Dmitri Mendeleev How did he line up the elements?
Left blank spaces for unknown elements

13. Henry Moseley ( )
1913
British physicist – determined atomic number
Lines up atoms by increasing atomic number

14. Today’s Periodic Table
Glenn Seaborg
Lanthanides &
Actinides

15. Alkali metals
Alkaline earth metals
Transition Metals

16. Alkali metals
Alkaline earth metals
Transition Metals

17. Alkali metals
Alkaline earth metals
Transition Metal

18. Non-metals
Noble gases

19. Non-metals
Noble gases

20. Non-metals
Noble gases
Halogens
Metalloids

21. Non-metals
Noble gases
Halogens
Metalloids

22. Periods – horizontal rows
Seven periods
Properties change when move across period

23. Periodic Law Properties repeat from one period to next
Periodic Law – periodic repetition of physical & chemical properties

24. Elements with similar properties are in same column.
Group/family- Vertical column 1A, 2A, 3A, etc.

25. Identified by number & letter Column 1A
Identified by number & letter Column 1A ? React vigorously with water (explosive)

26. Periodic Trends
Atomic Radius
Decrease
Increase

27. Atoms lose electrons to form cations (positive)
Empty orbital
Repulsion is less between electrons

28. Atoms gain electrons to form anions (negative)
Repulsion is increased between electrons = cloud gets bigger

29. Ionic Radius Increases 5A, 6A, 7A all Gain electrons Larger Smaller
decreases
5A, 6A, 7A all Gain electrons
Increases

30. Ionization Energy energy required to remove an electron from a
gaseous atom.

31. Ionization Energy –
Increases
Decreases

32. Octet Rule – (John Newlands)
Atoms tend to gain, lose or share electrons to acquire a full set of valence electrons.

33. Electronegativity
Ability to attract electrons in a chemical bond.

34. Periodic Trends
Electronegativity –
Increases
Decreases

35. Reactivity of metals and non-metals
Most reactive metal ? Francium low electronegativity

36. Most reactive non-metal ? Fluorine
high electronegativity

37. Properties Metals – high conductivity & high luster
Ductile (pull into wire)
Malleable (sheets)

38. Representative elements
80% of elements are metals
Usually solid at room temp. Except? Hg

39. Non-metals
Upper right corner of table
Non-lustrous
Poor conductors

40. Non-metals
Gas O Cl
Brittle solid S
Group 7A – Halogens

41. Non-metals Group VIII A – noble/inert gas undergo very few reactions
Heavy stair-step line - metalloids

42. Non-metals Metalloids – between metals & non-metals
Properties between both
Si & Ge – computer chips and solar cells

43. Reactivity of Metals Ability of a metal to undergo a chemical change
Lose electrons

44. Reactivity of Metals
decreases
INCREASES

45. Reactivity of Non-Metals
INCREASES
decreases