1. THE PERIODIC TABLE

2. PERIODIC
When something occurs at regular intervals (you can predict what happens / comes next)

3. So what makes the periodic table periodic?
ATOMIC NUMBER!!!
(across the chart)

4. PERIODIC LAW
The properties of the elements are a periodic function of their atomic numbers

5. .

6. All of the elements in a horizontal row
PERIOD
All of the elements in a horizontal row

7. All of the elements in a vertical column (aka Family)
GROUP
All of the elements in a vertical column (aka Family)

8. invented the periodic table based on increasing atomic mass
Dmitri Mendeleev ( )
invented the periodic table based on increasing atomic mass
…and yes, he too, is your friend

9. revised the periodic table based on properties and
Henry Moseley (1913)
revised the periodic table based on properties and
atomic number
…and yes, he too, is your friend

10. ALKALI METALS
s1 group
Good Conductors

11. ALKALINE EARTH METALS
Group 2
Harder, more dense, stronger than alkali

12. TRANSITION METALS
Groups 3-11

13. LANTHANOID SERIES
4f sub energy level
Z = 57-70

14. ACTINOID SERIES 5f sub energy level Z = 89-102
All have radioactive forms (unstable p+ & N°)

15. 13, 14, 15, 16 are named by the first element in the column
Columns
13, 14, 15, 16 are named by the first element in the column
(e.g. Boron Group)

16. HALOGENS
Group 17
Combine with metals to form salts
Very reactive

17. NOBLE GASES
Group 18
Inert gases (not reactive)
8 valence electrons

18. Stability of e-configurations

19. The eight outer electrons in an atom
OCTET
The eight outer electrons in an atom

20. Atoms with full outer energy levels are very stable (less reactive)
FACT:
Atoms with full outer energy levels are very stable (less reactive)

21. OCTET RULE
If an atom has 8 electrons in its outer energy level, it is unreactive (except He, which is full at 2).

22. Now…how do we make ENERGY LEVELS more stable?

23. Ways to make full outer energy levels:
Add electrons to a partially filled outer energy level
Lose all electrons in the outer energy level
Share electrons with another atom

24. Periodic Trends

25. ATOMIC RADIUS
The distance from the center of the nucleus to the outermost energy level

26. The atomic radius INCREASES within a family
(just adding energy levels)

27. The atomic radius DECREASES within a period
(more positive charge pulling e-)

30. SHIELDING EFFECT
The positive pull is less because the distance between nucleus and electrons is greater

31. IONIZATION ENERGY the energy required to remove an electron from an atom

32. The ionization energy DECREASES as you go down a family
(shielding effect)

33. The ionization energy INCREASES across a period
(more p+ have more pull on e-)

36. ELECTRON AFFINITY how much an atom desires another electron

37. The electron affinity DECREASES as you go down a family
(shielding effect)

38. (more p+ have more pull on e-)
The electron affinity INCREASES across a period (except for the noble gases)
(more p+ have more pull on e-)

40. ELECTRONEGATIVITY The tendency of an atom to attract electrons to itself when it is bonded to another atom

41. The electronegativity DECREASES as you go down a family
(shielding effect)

42. The electronegativity INCREASES across a period
(more p+ have more pull on e-)