1. The Periodic Table and Periodic Law
Chapter 6
The Periodic Table and Periodic Law

2. Chapter 6 Terms Group Period Ion Nonmetal Representative element
Transition element
Metal
Alkali metal
Alkaline earth metal
Nonmetal
Halogen
Noble gas
Metalloid
Atomic radius
Ionization energy
Electronegativity
Draw a periodic table.
Label you PT using each term above (not ion).
Draw arrows to define atomic radius, ionization energy, and electronegativity from inc to dec or dec to inc.

3. Development of the Modern Periodic Table
Chapter 6.1
Development of the Modern Periodic Table

4. Behavior of Main Group Elements
Elements in the same group (vertical column) of the periodic table have the same number of valence electrons, and because of this, they have similar properties.
But elements in a period (horizontal row) have properties different from one another.

5. Behavior of Main Group Elements
This is because the number of valence electrons increases from one to eight as you move from left to right.
As a result, the character of the elements changes.

6. Behavior of Main Group Elements
Each period begins with two or more metallic elements, which are followed by one or two metalloids.
The metalloids are followed by nonmetallic elements, and every period ends with a noble gas.

7. Trends in Metallic Properties
Periods

8. Elements
Representative elements are the groups designated with an A (1A through 8A)
Transition elements are the groups designated with a B (1B through 8B)

9. Classifying Elements Metals Nonmetals Metalloids
Three main classes of elements
Metals
Nonmetals
Metalloids

10. Classifying Elements: Metals
Shiny
solid at room temperature (r.t.)
good conductors of heat and electricity.
malleable and ductile

11. Classifying Elements: Metals
Alkali Metals: Group 1A elements
Alkaline Earth Metals: Group 2A elements
Both are chemically reactive, with alkali metals being more reactive than alkaline earth metals.

12. Classifying Elements: Metals
Transition Metals: Group B elements, are divided into 2 categories
Inner Transition Metals: Two sets of series, lanthanide and actinide (more in Chap. 7). They are located along the bottom of the PT.
Transition Metals: Make up the rest of Group B elements

13. Classifying Elements: Metals
Nonmetals: Occupy the upper right side of the PT (yellow boxes).
gases or brittle,
dull looking solids.
Poor conductors of heat and electricity.
Bromine is the only nonmetal that is liquid at r.t.
Halogens: Group 7A elements. Highly reactive.
Noble Gases: Group 8A elements. Highly unreactive.

14. Classifying Elements: Metals
Metalloids: The green boxes that are the zigzag line separating the metals and nonmetals.
They have physical and chemical properties of both metals and nonmetals.

15. Chapter 6.3
Periodic Trends

16. Atomic Radii
Atom size increases in a group of elements as you go down because valence electrons are found in energy levels farther from the nucleus.
Atom size decreases in a period because the outer electrons are attracted more strongly toward the nucleus.
Figure 6.11c Page 163

17. Atomic Radii = 1 Angstrom IA IIA IIIA IVA VA VIA VIIA Li Na K Rb Cs ClP Si Al Br Se As Ge Ga I Te Sb Sn In Tl Pb Bi Mg Ca Sr Ba Be F O N C B
= 1 Angstrom 17

18. Ionic Radius
Atoms can gain or lose one or more electrons to form ions.
Because electrons are negatively charged this causes atoms to acquire a net charge
An ION is an atom that has a positive or negative charge.
How does the formation of an ion affect the size of an atom???

19. Ionic Radius: Trends in Periods
As you move left to right across a period the size of positive ions gradually decreases.
Once you get to 5A or 6A the size of the larger negatively charged atoms becomes smaller.
Check out Figure 6.14 on Page 166 for a diagram.

20. Ionic Radius: Trends in Groups
As you move down in a group the size increases.
This is for both positive and negative ions
Check out Figure 6.14 on Page 166 for a diagram.

21. Ionic Radii Atomic Radii = 1 Angstrom = 1 Angstrom
0.95
IA IIA IIIA IVA VA VIA VIIA
= 1 Angstrom
Li1+
Be2+
Na1+
Mg2+
Ba2+
Sr2+
Ca2+
K1+
Rb1+
Cs1+
Cl1-
N3-
O2-
F1-
S2-
Se2-
Br1-
Te2-
I1-
Al3+
Ga3+
In3+
Tl3+
IA IIA IIIA IVA VA VIA VIIA Li Na K Rb Cs Cl S P Si Al Br Se As Ge Ga I Te Sb Sn In Tl Pb Bi Mg Ca Sr Ba Be F O N C B
= 1 Angstrom 21

22. Ionization Energy To form the positive ion you need ENERGY!
The energy needed is to overcome the attraction between the positive energy in nucleus and the charge of the electron. This is the IONIZATION ENERGY
I.E. can be thought of as an indication of how strongly an atom’s nucleus holds onto the valance electrons.

23. Ionization Energy
A high I.E. means the atom has a strong hold on its valance electrons.
A low I.E. means the atom loses its valance electrons easily.
It is possible for atoms to lose of gain more than one electron. The amount of energy required to do this is called the second ionization energy. So the third is…

24. Ionization Energies Period H He Mg Li Be B C N O F Ne Na Mg Al Si P S
Group 1 18 H
1312 He
2372 1 1 Mg
738
Symbol
First Ionization Energy
(kJ/mol) 2 13 14 15 16 17 Li
520 Be
900 B
801 C
1086 N
1402 O
1314 F
1681 Ne
2081 2 2 Na
496 Mg
738 Al
578 Si
787 P
1012 S
1000 Cl
1251 Ar
1521 3 3 3 4 5 6 7 8 9 10 11 12
Period K
419 Ca
590 Sc
633 Ti
659 V
651 Cr
653 Mn
717 Fe
762 Co
760 Ni
737 Cu
746 Zn
906 Ga
579 Ge
762 As
947 Se
941 Br
1140 Kr
1351 4 4 Rb
403 Sr
550 Y
600 Zr
640 Nb
652 Mo
684 Tc
702 Ru
710 Rh
720 Pd
804 Ag
731 Cd
868 In
558 Sn
709 Sb
834 Te
869 I
1008 Xe
1170 5 5 Cs
376 Ba
503 La
538 * Hf
659 Ta
761 W
770 Re
760 Os
839 Ir
878 Pt
868 Au
890 Hg
1007 Tl
589 Pb
716 Bi
703 Po
812 At -- Rn
1038 6 6 Fr -- Ra
509 Ac
490 y Rf -- Db -- Sg -- Bh -- Hs -- Mt -- Ds --
Uuu --
Uub --
Uut --
Uuq --
Uup --
Uuo -- 7 *
Lanthanide series Ce
534 Pr
527 Nd
533 Pm
536 Sm
545 Eu
547 Gd
592 Tb
566 Dy
573 Ho
581 Er
589 Tm
597 Yb
603 Lu
523 y
Actinide series Th
587 Pa
570 U
598 Np
600 Pu
585 Am
578 Cm
581 Bk
601 Cf
608 Es
619 Fm
627 Md
635 No
642 Lr -- 24

25. Electronegativity
Electronegativity indicates the relative ability of its atom to attract electrons.
As you move from left to right in a period the electronegativity increases.
As you move down in a group the electronegativity decreases.
The lower left side of the periodic table has the lowest and the upper right has the highest!!

26. Electronegativities Period H B P As Se Ru Rh Pd Te Os Ir Pt Au Po At
2.1 B
2.0 P As Se
2.4 Ru
2.2 Rh Pd Te Os Ir Pt Au Po At 1 1 2A 3A 4A 5A 6A 7A
Actinides: Li
1.0 Ca Sc
1.3 Sr Y
1.2 Zr
1.4 Hf Mg La
1.1 Ac
Lanthanides: * y Be
1.5 Al Si
1.8 Ti V
1.6 Cr Mn Fe Co Ni Cu
1.9 Zn
1.7 Ga Ge Nb Mo Tc Ag Cd In Sn Sb Ta W Re Hg Tl Pb Bi C
2.5 S Br
2.8 I N
3.0 O
3.5 F
4.0 Cl 2 2 Na
0.9 K
0.8 Rb Cs
0.7 Ba Fr Ra
Below 1.0 3 3 3B 4B 5B 6B 7B 8B 1B 2B
Period 4 4 5 5 6 6 7 26

27. Summary of Periodic Trends
Atomic radius decreases
Ionization energy increases
Electronegativity increases 1A 2A 3A 4A 5A 6A 7A
Ionization energy decreases
Electronegativity decreases
Atomic radius increases
Ionic size increases
Ionic size (cations) Ionic size (anions)
decreases decreases 27