The Periodic Table
1 The Periodic Table
y Development of the periodic table (8.1) y Periodic classification of the elements (8.2) y Periodic variation in physical properties (8.3) y Ionization energy (8.4) y Electron affinity (8.5) y Variation in chemical properties of the representative elements (8.6) 8.1 and 8.2 Development of the periodic table and periodic classification
y In what year was the modern periodic table developed? y How was the periodic table put together? ns1 4f 5f
ns2 Ground State Electron Configurationsof the Elements d1
d5
d10 ns2np1
ns2np2
Figure 8.1, p. 255 ns2np3
ns2np4 ns2np5
ns2np6 8.1 and 8.2 Development of the periodic table and periodic classification
y In what year was the modern periodic table developed? y How was the periodic table put together?
y In what year were electrons discovered? y In what year were protons discovered? 8.1 and 8.2 Development of the periodic table and periodic classification When the Elements Were Discovered Elements Were When the 8.1 and 8.2 Development of the periodic table and periodic classification
Figure 8.2, p. 257 8.1 and 8.2 Development of the periodic table and periodic classification y What are core electrons? y How do these vary by period?
He (2 core e-) Ne (10 core e-) Ar (18 core e-) Kr (36 core e-) Xe (54 core e-) 8.1 and 8.2 Development of the periodic table and periodic classification y What are valence electrons? y How do these vary by group?
12 345678 8.1 and 8.2 Development of the periodic table and periodic classification
y How are electron configurations of ions determined and written? Electron Configurations of Cations and Anions of Representative Elements configuration. outer electron a noble-gas has that anion electrons so Atoms gain 8.1 and8.2 table andperiodic classification Ca [Ar]4s Na [Ne]3s Al [Ne]3s 2 2 1 3p 1 F 1s H 1s O 1s N 1s Development oftheperiodic Ca Al Na 3+ 2+ 2 + 2 1 2 2s 2s 2s [Ne] [Ne] [Ar] 2 2 2 2p 2p 2p 5 3 4 N O F H configuration. gas outerelectron cation hasanoble- electrons sothat Atoms lose - - 3- 2- 1s 1s 1s 1s 2 2 2s 2 2 or [He] 2s 2s 2 2p 2 2 2p 2p 6 6 6 or [Ne] or [Ne] or [Ne] +1 +2 Cations and Anions Of Representative Elements
+3
Figure 8.1, p. 255 -3 -2 -1 Electron Configurations of Cations of Transition Metals Fe Fe Fe: [Ar]4s orbital andthenfromthe ( metal, electronsarealways removedfirst from the isformedfromanatomofa transition When acation 8.1 and8.2 table andperiodic classification 3+ 2+ : [Ar]4s : [Ar]4s 2 0 0 3d 3d 3d 6 5 6 or [Ar]3d or [Ar]3d Development oftheperiodic 5 6 n –1) Mn Mn: [Ar]4s 2+ d : [Ar]4s orbitals. 2 0 3d 3d 5 5 or [Ar]3d ns 5 8.1 and 8.2 Development of the periodic table and periodic classification
y How are electron configurations of ions determined and written? y What is isoelectronic? y Which species are isoelectronic?
Na K Na+ K+ Ca2+ Ti4+ Ne Al3+ S2– Cl– Cl Ar O2– Sc2+ Kr 8.3 Atomic and Ionic size
y Do all electrons feel the same nuclear charge? y What is shielding? y What is effective nuclear charge? 8.3 Atomic and Ionic size
Na Mg Al Si P S Cl
Z 11121314151617
Core 10 10 10 10 10 10 10
Zeff 1234567
σ 8.8 9.15 9.5 9.85 10.2 10.55 10.9
Zeff 2.2 2.85 3.5 4.15 4.8 5.45 6.1 Effective Nuclear Charge Effective 8.3 Atomic and Ionic size
Li Na K Rb Cs Fr
Z 3 11 19 37 55 87
Core21018365486
Zeff 111111
σ 1.7 8.8 16.8 33.3 51.3 81.2
Zeff 1.3 2.2 2.2 3.7 3.7 5.8 Effective Nuclear Charge Effective Effective Nuclear Charge
Effective Nuclear Charge (Zeff) increases down a group from top to bottom 8.3 EffectiveNuclear Charge( Atomic andIonic size Z eff ) increases) across a periodfromto right left Margin Figure, p. 259 8.3 Atomic and Ionic size
y Do all electrons feel the same nuclear charge? y What is shielding? y What is effective nuclear charge? y How does this affect the size of atoms? ◦ How do we determine the size of atoms? 8.3 Atomic and Ionic size
Radius = ½ the distance between the centers of the atoms
Figure 8.3, p. 260 Atomic Size 8.3
Atomic size increases down a group Atomic andIonic size
from top to bottom Atomic sizedecreases across aperiodfromto right left Figure 8.2, p. 257 8.3 Atomic and Ionic size
y Do all electrons feel the same nuclear charge? y What is shielding? y What is effective nuclear charge? y How does this affect the size of atoms? ◦ How do we determine the size of atoms? y How does atomic size change when ions form? 8.3 Atomic and Ionic size
Cation is always smaller than atom from which it is formed. Anion is always larger than atom from which it is formed.
Figure 8.7, p. 262 Ionic Size 8.3 Atomic andIonic size Figure 8.6, p. 262 Ionic Size 8.3 Atomic andIonic size Figure 8.8, p. 263 8.4 Ionization energy
y What is ionization energy? y What is the periodic trend for ionization energy? 8.4 Ionization energy
Ionization Energy increases across a period from left to right group from top to bottom from group Ionization Energy decreases down a down Ionization Energy decreases
Margin Figure, p. 265 8.4 Ionization energy
Figure 8.9, p. 266 8.4 Ionization energy
y What is ionization energy? y What is the periodic trend for ionization energy? y What is the difference between 1st and successive ionization energies? 8.4 Ionization energy
Table 8.2, p. 265 8.5 Electron Affinity
y What is electron affinity? y How can this be represented in a thermochemical equation?
Table 8.3, p. 268 8.6 Descriptive Chemistry
y Read p. 268-278 y You will be tested on only those concepts that you have already been tested and/or taught. For example: ◦ The electron configuration of calcium ◦ The reaction of sodium with water ◦ The metallic character periodic trends (consider group 4) Chapter 8 – Practice