1. 4.06 Periodic Table and Periodic Trends
Dr. Fred Omega Garces
Chemistry 100, Miramar College

2. The Periodic Table and the Elements
What is the periodic table ?
What information is obtained from the table ?
How can elemental properties be predicted base on the PT ?

3. The Periodic Table A map of the building block of matter.
I like to refer to the periodic table as a map of the building block of matter. Consider the value of a map. A map of California for example shows you the terrain and geological information of California. According to the map, the east is the Sierra Nevada, the west is the Pacific Ocean, the north is Portland and south is Baja California. Like wise the periodic table provides valuable information. The PT shows family and periods. The southwest (lower-left) portion of the Periodic table are the most metallic while the northeast (upper-right) is the most nonmetallic. Other information about the periodic table will be describe in this chapter.

4. Periodic Table e- configuration from the periodic periodic table
Electron configuration of an element is simply a listing of how many electrons are in each energy level of the atom for a particular element. The best way to determine of an element is to use the periodic table. In lecture notes 3.5, this was discussed. H
1s1 He
1s2 Li
2s1 Be
2s2 B
2p1 B
2p1 C
2p2 N
2p3 O
2p4 F
2p5 Ne
2p6 Na
3s1 Mg
3s2 Al
3p1 Si
3p2 P
3p3 S
3p4 Cl
3p5 Ar
3p6 K
4s1 Ca
4s2 Sc
3d1 Ti
3d2 V
3d3 Cr
4s13d5 Mn
3d5 Fe
3d6 Co
3d7 Ni
3d8 Cu
4s13d10 Zn
3d10 Ga
4p1 Ge
4p2 As
4p3 Se
4p4 Be
4p5 Kr
4p6 Rb
5s1 Sr
5s2 Y
4d1 Zr
4d2 Nb
4d3 Mo
5s14d5 Tc
4d5 Ru
4d6 Rh
4d7 Ni
4d8 Ag
5s14d10 Cd
4d10 In
5p1 Sn
5p2 Sb
5p3 Te
5p4 I
5p5 Xe
5p6 Cs
6s1 Ba
6s2 La
5d1 Hf
5d2 Ta
5d3 W
6s15d5 Re
5d5 Os
5d6 Ir
5d7 Ni
5d8 Au
6s15d10 Hg
5d10 Tl
6p1 Pb
6p2 Bi
6p3 Po
6p4 At
6p5 Rn
6p6 Fr
7s1 Ra
7s2 Ac
6d1 Rf
6d2 Db
6d3 Sg
7s16d5 Bh
6d5 Hs
6d6 Mt
6d7

5. Periodic Table: electron behavior
The periodic table can be classified by the behavior of their electrons
It is important to note that when writing out the electron configuration for the elements, metals tend to have fewer electrons in their valence orbitals than nonmetals. When atoms try to attain the noble gas electron configuration, they tend to take the path of least resistance. Metals can attain a noble gas electron configuration more easily by losing electrons (therefore becoming cations) while nonmetals will attain a noble gas electron configuration by gaining electrons (therefore becoming anions).

6. 2. Trend in Atomic Radius Atomic Radius:
The size of at atomic specie is determine by the boundaries of the valence e-. Largest atomic species are those found in the southwest (SW) or bottom-left corner of the periodic table since these atoms have their valence electron found in a higher shell than the proceeding element above it in the periodic table. For example, elements with trends of increasing size goes, Li < Na , K < Rb for the Alkali family. For the chalcogen, the trend is O < S < Se < Te. Te has its valence electrons in the 5th shell and Se has its valence electrons in the 4th shell. Therefore, Te is bigger than O.
Across the periodic table, the atomic radius decreases. The smallest atoms are found in the northeast (NW) or top-right corner of the periodic table. This trend follows Z(effective), which means that for elements in the same period, the valence electrons are all found in the same shell. For a given period, elements to the right (east) of the periodic table have more protons than those to the left (west) of the periodic table. This effectively causes the electron cloud in the valence shell to contract towards the nucleus where they are attracted to the proton. Therefore, the atomic radius decreases across the periodic table. For the third period, the atomic radius essentially goes Al > Si > P > S > Cl > Ar. In this example, Chlorine is smaller than S because although Cl has 7 valence electrons found in the 3rd shell, these electrons are attracted by 17 protons. Sulfur on the other hand has six valence electrons attracted by only 16 protons. Seventeen protons attracting the valence electrons in chlorine is more effective in decreasing the atomic radius than sixteen protons of sulfur.

7. 2. Trend in Atomic Radius

8. 3. Trend in Ionization Potential
Ionization energy increases moving towards the NE corner or top-right corner of periodic table. The lowest ionization energy is towards the SW or bottom-left corner of the periodic table. The ionization energy is opposite the trend of atomic radii. This can be rationalize by thinking about the attraction of the valence electrons to the nucleus where the protons are located. For very small atoms, the valence electrons are closer to the protons and therefore the energy required to remove these valence electrons will be high. For larger atoms, the valence electrons are further away from the nucleus and therefore are not held as tightly. Larger atoms will have smaller ionization energy. There are some anomallies in this general trend that can be explained by how the electrons are arranged in the orbitals.
Exercise - In general the ionization energy increase when moving towards the non mental (right-top) portion of the periodic table. Why is it therefore that the ionization energy for oxygen (1314 kJ/mol is lower in energy than nitrogen 1402 kJ/mol, see table below
Ionization energy or potential energy is defined as the energy required to remove the valence electron from an atomic specie.

9. 3. Trend in Ionization Potential

10. 4. Trend in Electron Affinity
Electron affinity is defined as the energy released (therefore the negative sign, see table) when an electron is added to the valence shell of an atom.
The electron affinity is most favorable toward NE or upper right corner of periodic table since these atoms will have the greatest tendency to attract electrons. Smaller atoms will have an affinity for electrons more effectively than large atoms. Going from right to left, B, C, N, O, and F, the electron affinity is increasingly negative. The anomallies in the trend, ie., nitrogen, due to the electron placement going into a half-filled p-orbitals.

11. Periodic Table Live http://www.chemeddl.org/resources/ptl/index.php
About Periodic Table Live!: Program that allows a broad range of information about the elements, their reactions, their properties, their structures, and their histories.
Required Components: Apple QuickTime is required to view videos on this site.
Suggested Browsers: For the best user experience, we recommend one of the following browsers:

12. Summary of Trend Periodic Table and Periodic Trends
The periodic table contains valuable information about all atoms responsible for matter in our universe. The table can be thought of as a map in which information about physical characteristics and chemical behavior can be obtain. The table also organizes the elements in such a matter that trends in chemical behavior and physical properties can be realize. The following are easily obtain from the periodic table.
Electron Configuration
Metallic Character
3. Ionization Energy: Largest toward NE of PT
4. Electron Affinity: Most favorable NE of PT
2. Atomic Radius: Largest toward SW corner of PT

13. Summary Periodic Table: Map of the Building block of matter
Type: Metal, metalloid and Nonmetal
Groupings: Representative or main, transition and Lanthanide/Actanides
Family: Elements in the same column have similar chemical property because of similar valence electrons
Alkali, Alkaline, chalcogens, halogens, noble gases
Period: Elements in the same row have valence electrons in the same shell.

14. Summary

15. Answer these questions before your next quiz.
Define Ionization Energy (IE or IP) and Electron Affinity (EA).
What region of the periodic table are the largest elements found? What region of the periodic table are the smallest elements found?
What region of the periodic table are the elements with the highest ionization energy found? What region of the periodic table are the elements with the lowest ionization energy found?
What region of the periodic table are the elements with the smallest electron affinity found? What region of the periodic table are the elements with the largest electron affinity found?
Define metallic character. Give some properties of what makes one element more metallic than another?
Which part of the periodic table are the elements with the most metallic character found?
Explain why the atomic radius of elements decrease when going from left to right elements in period 4.
Why are there anomalies in terms of decreasing atomic radius when going from left to right in a period?
Why is the ionization energy for oxygen lower than nitrogen even though the trend is generally increasing ionization energy going from left to right in a period?
What are the trend of atomic radius, ionization energy and electron affinity when going from top to bottom in a family of elements.