3.06 Periodic Table and Periodic Trends

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1 3.06 Periodic Table and Periodic Trends Dr. Fred Omega Garces Chemistry 100, Miramar College Periodic Table and Periodic Trend

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? Periodic Table and Periodic Trend

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. 1 IA 1 1 H Li Periodic Table IIA IIIA 4 Be Na Mg K Rb Cs Fr [223] 20 Ca Sr Ba Ra [226] 3 IIIB 21 Sc Y La Ac [227] 4 IVB 22 Ti Zr Hf Ku [260] 5 VB 23 V Nb Ta VIB 24 Cr Mo W VIIB 25 Mn Tc [99] 75 Re VIIIB 26 Fe Ru Os Co Rh Ir IB 28 Ni Pd Pt Cu Ag Au IIB 30 Zn Cd Hg B Al Ga In Tl VIIIA IVA VA VIA VIIA He C N O F Ne Si Ge Sn Pb P As Sb Bi S Se Te Po [210] 17 Cl Br I At [210] 18 Ar Kr Xe Rn [222] Periodic Table and Periodic Trend

4 Periodic Table e - configuration from the periodic periodic table 1 1 IA H 1s 1 2 IIA 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. 13 IIIA 14 IVA 15 VA 16 VIA 17 VIIA 18 VIIIA He 1s 2 2 Li 2s 1 Be 2s 2 B 2p 1 B C 2p 12 N 2p 3 O 2p 4 F 2p 5 Ne 2p 6 3 Na 3s 1 Mg 3s 2 3 IIIB 4 IVB 5 VB 6 VIB 7 VIIB 8 9 VIIIB IB 12 IIB Al 3p 1 Si 3p 2 P 3p 3 S 3p 4 Cl 3p 5 Ar 3p 6 4 K 4s 1 Ca 4s 2 Sc 3d 1 Ti 3d 2 V 3d 3 Cr Mn 4s 1 3d 5 3d 5 Fe 3d 6 Co 3d 7 Ni 3d 8 Cu 4s 1 3d 10 Zn 3d 10 Ga 4p 1 Ge 4p 2 As 4p 3 Se 4p 4 Be 4p 5 Kr 4p 6 5 Rb 5s 1 Sr 5s 2 Y 4d 1 Zr 4d 2 Nb 4d 3 Mo 5s 1 4d 5 Tc 4d 5 Ru 4d 6 Rh 4d 7 Ni 4d 8 Ag 5s 1 4d 10 Cd 4d 10 In 5p 1 Sn 5p 2 Sb 5p 3 Te 5p 4 I 5p 5 Xe 5p 6 6 Cs 6s 1 Ba 6s 2 La 5d 1 Hf 5d 2 Ta 5d 3 W 6s 1 5d 5 Re 5d 5 Os 5d 6 Ir 5d 7 Ni 5d 8 Au 6s 1 5d 10 Hg 5d 10 Tl 6p 1 Pb 6p 2 Bi 6p 3 Po 6p 4 At 6p 5 Rn 6p 6 7 Fr 7s 1 Ra 7s 2 Ac 6d 1 Rf 6d 2 Db 6d 3 Sg 7s 1 6d 5 Bh 6d 5 Hs 6d 6 Mt 6d Periodic Table and Periodic Trend

5 1 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). 1 IA 2 IIA 13 IIIA 14 IVA 15 VA 16 VIA 17 VIIA 18 VIIIA IIIB 4 IVB 5 VB 6 VIB 7 VIIB 8 9 VIIIB IB West (South) Mid-plains East (North) METALS Alkali Alkaline Transition These elements tend to give up e - and form CATIONS METALLOID These elements will give up e - or accept e - 12 IIB NON-METALS Noble gas Halogens Calcogens These elements tend to accept e - and form ANIONS Periodic Table and Periodic Trend

6 Atomic Radius: 2. Trend in 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 Periodic Table and Periodic Trend

7 2. Trend in Atomic Radius Periodic Table and Periodic Trend

8 3. Trend in Ionization Potential Ionization potential: Ionization energy or potential energy is defined as the energy required to remove the valence electron from an atomic specie. Ionization energy increases moving towards the NE corner or topright 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 Periodic Table and Periodic Trend

9 3. Trend in Ionization Potential Periodic Table and Periodic Trend

10 4. Trend in Electron Affinity 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 Periodic Table and Periodic Trend

11 4. Trend in Electron Affinity Periodic Table and Periodic Trend

12 Periodic Table Live 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: Periodic Table and Periodic Trend

13 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. 1. Electron Configuration 2. 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 Periodic Table and Periodic Trend

14 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 Periodic Table and Periodic Trend

15 Summary Periodic Table and Periodic Trend