1. Chapter 6: The Periodic Table

2. Organizing the Elements
Demitri Mendeleeve (Russian – 1869)
Published the 1st periodic table
Based on atomic mass

3. The Periodic Law Modern Periodic Table
Organized according to atomic number
Periods = rows 1-7
equal to the principal energy level
Groups = columns 1-18
elements have similar properties
Law: Properties of elements repeat as you move from Left → Right across a period

4. Period →
Group ↓

5. Metallic Character Approx. 2/3 of the elements are metals
Metallic Properties
Luster
Conductivity
Malleability
Ductility
Tend to lose electrons
Nonmetallic Properties
Dull luster
Poor conductors
Brittle
Tend to gain electrons
Metalloids (semimetals)
Some properties characteristic of metals and other properties characteristic of nonmetals

6. METALS Metals and Nonmetals Nonmetals Metalloids H He Li Be B C N O F1 He 2 1 Li 3 Be 4 B 5 C 6 N 7 O 8 F 9 Ne 10 2
Nonmetals Na 11 Mg 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 3 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 4
METALS Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 5
Metalloids Cs 55 Ba 56 He 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 6 * Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 7 W La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm
100 Md
101 No
102 Lr
103

7. Reference Table
Periodic Table
Trends:
1. Across a period, metallic character →
Why?
More electrons in outer shells
Less tendency to lose electrons
2. Down a group, metallic character →
Less electrons in outer shells
Greater tendency to lose electrons
decreases
increases

8. Metallic Review
Identify each element as a metal, nonmetal or metalloid
Gold -
Silicon -
Sulfur -
Barium -
Metal
Metalloid
Nonmetal
Metal

9. Which of these sets of elements have similar physical and chemical properties?
oxygen, nitrogen, carbon,
strontium, magnesium, calcium, beryllium
nitrogen, neon, , fluorine
Name 2 elements that have properties similar to those of the element sodium.
boron
nickel
Any other Group 1 element:
Lithium, Potassium, Rubidium, Cesium, Francium

10. Identify each property below as more characteristic of a metal or a nonmetal
Brittle -
Malleable -
Poor conductor of electricity -
Shiny -
Tend to gain electrons -
In which pair of elements are the chemical properties of the elements most similar?
sodium and chlorine
nitrogen and phosphorus
boron and oxygen
Nonmetal
Metal
Nonmetal
Metal
Nonmetal

11. Classifying the Elements
Alkali Metals –
Alkaline Earth Metals –
Halogens –
Noble Gases –
Representative Elements –
Transition Elements –
Group 1 (1A)
Group 2 (2A)
Group 17 (7a)
Group 18 (8A) Inert gases
Groups 1A – 7A
All Group B

12. Label your Reference Periodic Table…1 18 H 1 He 2 1 2 13 14 15 16 17 Li 3 Be 4 B 5 C 6 N 7 O 8 F 9 Ne 10 2 Na 11 Mg 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 3 3 4 5 6 7 8 9 10 11 12 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 4 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 5 Cs 55 Ba 56 He 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 6 * Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 7 W La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm
100 Md
101 No
102 Lr
103

13. Classifying Review
Which of the following are symbols for representative elements
Na, Mg, , Cl?
Which of these metals is not a transition metal?
Aluminum
Silver
Iron
Zirconium
Fe, Ni

14. Atomic Radius Atoms are roughly spherical
Sphere size can be determined using the radius
Problem:
Edges of orbitals are fuzzy and difficult to measure…
Solution:
Atomic Radii – half the distance between the nuclei of identical atoms that are bonded together

15. Reference Table:
Table S
Trends:
1. Across a period, the atomic radius →
Why?
Nuclei have larger positive charges
Electrons are pulled in closer
2. Down a group, the atomic radius →
Greater number of energy shells
Valence electrons are further away from the nucleus
decreases
increases

17. Atomic Radius Review
Which element in each pair has a larger atomic radius?
& lithium
& bromine
carbon &
& neon
Arrange these elements in order of decreasing atomic size: sulfur, chlorine, aluminum, and sodium.
Sodium → Aluminum → Sulfur → Chlorine
sodium
calcium
germanium
fluorine

18. Ionization Energy What is an ion? An electrically charged atom
Atoms may either gain or lose electrons
Loss of electrons = (+) charge →
Gain of electrons = (-) charge →
Ionization energy =
cation
anion
the amount of energy required to
remove the most loosely bound
electron
A + energy  A+ + e-

19. Inverse Reference Table Table S Trends:
1. Across a period, the ionization energy →
Why?
Electrons are held closer to the nucleus
Electrons are more difficult to remove
2. Down a group, the ionization energy →
Electrons are further away from the nucleus
Electrons are easier to remove
Relate Back:
increases
decreases
What type of relationship exists between
ionization energy and atomic radii?
Inverse

21. Ionization Review
Which element in each pair has a greater ionization energy?
lithium,
magnesium,
cesium,
Arrange the following groups in order of increasing ionization energy
Be, Mg, Sr
Bi, Cs, Ba
Na, Al, S
boron
strontium
aluminum
Be → Mg → Sr
Bi → Ba → Cs
Na → Al → S

22. Ionic Size Cations from when atoms loose e- The cation is smaller
Anions from when
atoms gain e-
The anion is larger

23. Reference Table
No true table
Trends:
1. Across a period, ionic size →
Why?
When e- are lost, the attraction between the remaining e- increases
e- are drawn closer to the nucleus
2. Down a group, ionic size →
Increased atomic radius
e- are further away from the nucleus
decreases
increases

25. Ion Size Review
Which particle has the larger radius in each atom/ion pair?
Na, S, I,
Al,
The ions Na+ and Mg2+ each have 10e-. Which ion would you expect to have a smaller ionic radius?
Mg2+ atomic radius is smaller & e- are pulled in closer
Na+
S2- I-
Al3+

26. Electronegativity
A measure of the ability of an atom to attract a pair of electrons when bonded to another atom
Ability to ‘pull’ electrons from another atom
Electrons pulled closer:
Electrons pulled away:

27. Reference Table
Table S
Trends:
1. Across a period, the electronegativity →
Why?
Atoms are very close to a stable octet
‘Pull’ electrons from other atoms
2. Down a group, the electronegativity →
Top atoms have few electrons, and hold them tightly
Bottom atoms have numerous electrons and little desire to acquire more
increases
decreases

29. Electronegativity Review
Which element in each pair has a higher electronegativity value?
Cl, C,
Mg,
As,
Which element in each pair has a greater attraction for electrons?
Ca or
O or S F N Ne Ca O F
or K

30. Variation across a Period
Summary
Periodic Property
Variation across a Period
Variation down a Group
Metallic Character
Decreases
Increases
Atomic Radius
Decreases
Increases
Ionization Energy
Increases
Decreases
Ion Size
Decreases
Increases
Electronegativity
Increases
Decreases