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the periodic table.
for (4) understandingThe interconnected network of ideas
A Chemical Rebus
networks interconnected
- s
HIO4, periodic acid – H+ (acid) =
The Interconnected Network of Ideas for Understanding the
Periodic Table• Periodic Law• Uniqueness Principle• Diagonal Effect• Inert Pair Effect• Metal/Non-Metal Line• Acid-Base Properties of
Oxides• Standard Reduction
Potentials• p-d Interactions
Periodic Law Uniqueness Principle
Diagonal Effect
Inert Pair Effect
Metal Non-Metal Line
The First Five Components of the Network of Ideas
Periodic Law
A periodic repetition of physical and chemical properties occurs when the elements are arranged in order of increasing atomic number.
Figure 9.9 A Summary of the General Vertical and Horizontal Periodic Trends in Effective Nuclear Charge (Zeff), Atomic Radii (r), Ionization Energy (IE), Electron Affinities (EA), and Electronegativities (EN). This Representation of the Periodic Law Is the First Component of the Interconnected Network of Ideas for Understanding the Periodic Table.
Zeff inc left to right ; const vertically
Radii decrease up and to the right
IE, EA, EN increase up and to the right
Uniqueness Principle
The chemistry of the second period elements (Li, Be, B, C, N, O, F, Ne) is quite often significantly different from that of the other elements in their respective groups.
Figure 9.13 A summary of three reasons for the uniqueness principle.
(a) The small size of the elements leading to a high degree of polarizing power and a high degree of covalent character in their compounds.
(b) The greater probability of pi bonds.
(c) The lack of availability of d orbitals.
Figure 9.10
(*) Charge density: the charge-to-radius ratio of a cation or anion; taken to be directly proportional to polarizing power (the ability to produce an induced dipole) of that ion.
The high charge density of the lithium ion polarizes the chloride ion and enhances the covalent character of the Li-Cl bond
Figure 9.11
Due to the small size of the period 2 elements, π-bonds (specifically so-called pπ-pπ bonds) are more likely to form.
Diagonal Effect
A diagonal relationship exists between the chemistry of the first member of a group and that of the second member of the next group
Figure 9.15 The elements of the diagonal effect. Lithium and magnesium, beryllium and aluminum, and boron and silicon, each pair diagonally located, have similar properties.
Inert Pair Effect
The valence ns2 electronic of metallic elements, particularly those 5s2 and 6s2 pairs that follow the second- and third-row transition metals, are less reactive than we would expect on the basis of trensds in effective nuclear charge, atomic sizes, and ionization energies.
Metal Non-Metal Line
The stepwise diagonal metal/nonmetal line divides the metals (to the bottom left of the line) from the nonmetals (to the top right of the line. The semi-metals (B, Si, Ge, As, Sb, Te, and At) are pictured along the line.
Figure 9.18 The metal-nonmetal line
The First Five Components of the Interconnected Network of Ideas
Periodic trends in Zeff, IE, EA, EN and r
(a) Uniqueness Principle(b) Diagonal Effect
(c) Inert Pair Effect
(d) Metal-Nonmetal Line
Figure 9.18,Front Left Cover & p.227
The Sixth Component
MO =H2O=>M+ + OH-
NMO =H2O=>H3O+ + NMO-
The Acid-Base Character of Oxides
Figure 11.16 Front Right Cover (color) & p. 284 (B/W)
The Seventh Component
Trends in Standard Reduction Potentials
Good Oxidizing
Agents
Good Reducing
Agents
Figure 12.5, Back Left
Cover (color) & p 318 (B/W)
Eo = Standard Reduction Potential
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