1. Periodic Trends: All Arrows point to increases
Electronegativity, Ionization Energy, Electron Affinity Atomic Radius, Ionic Radius, Metallic Character Melting & Boiling Point Reactivity

2. Follow along in your text Chapter 4 Sections 1 & 2 Pages 116 - 131
Periodic Table
Follow along in your text Chapter 4 Sections 1 & 2 Pages

3. Newlands John Newlands (1865, English)
Organized elements by increasing atomic mass.
Elements with similar properties were grouped together.
Created Law of Octaves.
Every 8 elements, there is a similarity.

4. Mendeleev Dmitri Mendeleev (1869, Russian)
Used Newlands’ Law of Octaves to create the first Periodic Table.
There were some discrepancies.

5. Mendeleev
Predicted properties of undiscovered elements.

6. Moseley Henry Mosely (1913, British)
Organized elements by increasing atomic number.
Resolved discrepancies in Mendeleev’s arrangement.

7. Periodic Blocks Main Group Elements (s &p) Transition Metals (d)
Inner Transition Metals (f)

8. Blocks of the Periodic Table

9. Periodic Law
When elements are arranged in order of increasing atomic #, elements with similar properties appear at regular intervals.

10. Let’s Get Organized!
Vertical columns are called “groups” or families
Same group = same number of valence electrons

11. Let’s Get Organized!(cont.)
Horizontal rows are called “periods”
Elements in each row have the same amount of principal energy levels occupied

12. 4 groups have special names
Main-Group Elements
Are in s & p blocks
Silicon & oxygen account for 4 of every 5 atoms found on or near Earth’s surface
4 groups have special names

13. Group 1: Alkali Metals
React with water to make alkaline solutions (reactive)
Never in nature as lone elements but are in compounds
1 valence electron
Li, Na, K, Ru, Cs, Fr

14. Group 2: Alkaline-Earth Metals
Hardly in nature as lone elements but are usually in compounds (highly reactive but not as much as Group 1)
2 valence electrons
Be, Mg, Ca, Sr, Ba, Ra

15. Groups 3 - 12: Transition Metals
Called d-block elements because in the center of the table
Do not always have the same outer configurations but their outer s & d orbitals will have the total amount of electrons as their group number
Can 1, 2, or 3 valence e- depending on the element with which it reacts

16. Most reactive nonmetals 7 valence electrons F, Cl, Br, I, At
Group 17: Halogens
Most reactive nonmetals
7 valence electrons
F, Cl, Br, I, At

17. Group 18: Noble Gases
Once call inert gases because once thought to be nonreactive
Full set of electrons in outermost energy level
Except He, all have config of ns2np6
He, Ne, Ar, Kr, Xe, Rn

18. Lanthanides & Actinides
(La # & Ac # )
Called the f-block elements
Lanthanides are similar in reactivity to alkaline-earth metals
Actinides are all radioactive due to their unique nuclear structure

19. Most common element in universe (3 of 4 atoms)
Lonely Hydrogen
Most common element in universe (3 of 4 atoms)
Only 1 electron so reacts with just about anything

20. Metals Most elements are metal
Excellent conductors of electricity & heat
Some are brittle; others are ductile (can be made into wire) & malleable (can be hammered into sheets)
Can be mixed with other elements to form alloys (mixtures that improve disadvantages of metals)

21. Metallic Characteristics
Metals
Nonmetals
Metalloids

22. Chemical Reactivity Families
Similar valence e- within a group result in similar chemical properties

23. Chemical Reactivity Alkali Metals Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases

24. Periodic Properties Atomic Radius size of atom
Measured by half of bond distance
© 1998 LOGAL
First Ionization Energy
Energy required to remove one e- from a neutral atom.
© 1998 LOGAL
Melting/Boiling Point

25. Atomic Radius
Atomic Radius
Increases to the LEFT and DOWN

26. Atomic Radius K Na Li Ar Ne

27. Atomic Radius Why radius larger going down?
Higher energy levels have larger orbitals
Shielding - core e- block the attraction between the nucleus and the valence e-
Why smaller to the right?
Increased nuclear charge without additional shielding pulls e- in tighter

28. Ionization Energy First Ionization Energy
Increases UP and to the RIGHT

29. Ionization Energy
First Ionization Energy He Ne Ar Li Na K

30. Ionization Energy Why opposite of atomic radius?
In small atoms, e- are close to the nucleus where the attraction is stronger
Why small jumps within each group?
Stable e- configurations don’t want to lose e-

31. Melting/Boiling Point
Highest in the middle of a period.

32. Ionic Radius Ionic Radius Cations (+) lose e- smaller Anions (–)
gain e-
larger
© 2002 Prentice-Hall, Inc.

33. Ionic Radius
Increases DOWN and to the LEFT for each type of ion

34. Examples
Which atom has the larger radius?
Be or Ba
Ca or Br Ba Ca

35. N or Bi Ba or Ne N Ne Examples
Which atom has the higher 1st Ionization Energy?
N or Bi
Ba or Ne N Ne

36. Li or C Cr or Kr C Cr Examples
Which atom has the higher melting/boiling point?
Li or C
Cr or Kr C Cr

37. S or S2- Al or Al3+ S2- Al Examples
Which particle has the larger radius?
S or S2-
Al or Al3+
S2- Al

38. Electronegativity
Numerical value of how much an atom in a molecule attracts electrons
Scale created by Linus Pauling
Flourine is 4.0 & other elements are calculated relative to this value

39. Electronegativity Increases UP and to the RIGHT
Same as Ionization Energy

40. Electron Affinity
The energy change that occurs when a neutral atom gains an electron
This is also due to increasing nuclear charge
Literally means “love of electrons”

41. Electron Affinity Increases UP and to the RIGHT
Same as Ionization Energy & Electronegativity

42. Examples
Which atom is most electronegative?
N or Bi
Ba or Rb N Ba

43. Be or Ba Ca or Br Be Br Examples
Which atom has the highest electron affinity?
Be or Ba
Ca or Br Be Br

44. Examples
Which atom is more metallic?
S or Fr
Al or Ge Fr Ge

45. Summary of Trends
Ionization Energy, Electronegativity, Electron Affinity all Increase UP & RIGHT
Atomic Radius & Ionic Radius all Increase DOWN & LEFT
Boiling/Melting point Increases then Decreases across blocks
Metals are to the left of the “stairs” & non-metals are to the right