Chapter_07-PropertiesOfElements

Chapter_07-Propertie - Chapter 7 Properties of elements Chapter Electronic structure and properties of elements Chapter 7 Properties of elements

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Unformatted text preview: Chapter 7. Properties of elements Chapter Electronic structure and properties of elements Chapter 7. Properties of elements Chapter Elements Chapter 7. Properties of elements Chapter Periodic table was first published in 1869 independently by • Dmitrii Mendeleev • Lothar Meyer Chapter 7. Properties of elements Chapter Periodic table was initially built according to the increase of atomic weights, but ~ 40 years later (1913, H.Moseley) the order of elements was correctly assigned to the increase of the number of protons in nucleus. Chapter 7. Properties of elements Chapter Periodic table styles Chapter 7. Properties of elements Chapter Periodic table styles Chapter 7. Properties of elements Chapter Periodic table styles Chapter 7. Properties of elements Chapter Periodic table styles Chapter 7. Properties of elements Chapter Periodic table styles Chapter 7. Properties of elements Chapter History – discovering elements Chapter 7. Properties of elements Chapter Trends in melting point Chapter 7. Properties of elements Chapter Trends in densities Chapter 7. Properties of elements Chapter Prediction power of the periodic table Chapter 7. Properties of elements Chapter Effective nuclear charge Basic properties Na atom The rule: because of not-complete screening of positive charge of a Chapter 7. Properties of elements Chapter Effective nuclear charge 1s 2s,2p 1s 2s,2p 1s 3s,3p Basic properties Chapter 7. Properties of elements Chapter Effective nuclear charge Basic properties Effective nuclear charge, e Zeff = Z - S Nucleus charge (number of protons in nucleus), e Screening constant (close to number of core electrons), e Chapter 7. Properties of elements Chapter Effective nuclear charge Basic properties Charge felt by innermost 1s electrons Charge felt by outermost electrons Chapter 7. Properties of elements Chapter Sizes of atoms Basic properties Van der Vaals radius “Atoms in motion” animation shows that free atoms behave like solid balls. Chapter 7. Properties of elements Chapter Trends in sizes of atoms Basic properties Chapter 7. Properties of elements Chapter Trends in sizes of atoms Which member of each pair has the Which greater atomic radius? Why? greater F or Cl or N or O or O or F or Na or Mg Na K or Na or Basic properties Chapter 7. Properties of elements Chapter Sizes of ions, Å Basic properties Chapter 7. Properties of elements Chapter Ionization energy Basic properties Ionization energy measures how strong an atom holds electron. Ionization energy, kJ/mol, is energy needed to remove electron from atom completely to create positive ion: First ionization step: Na(g) Na+(g) + eSecond ionization step Na+(g) Na2+(g) + eEtc… Chapter 7. Properties of elements Chapter Ionization energy Basic properties Sharp increase in ionization energy happens when all outer shell electrons have left the atom and the inner electrons are being removed. Chapter 7. Properties of elements Chapter Trends in ionization energy Basic properties Chapter 7. Properties of elements Chapter Ionization energy What element is this? Basic properties Chapter 7. Properties of elements Chapter Electron affinity Basic properties Electron affinity measures the ease with which atom gains an electron. Electron affinity, kJ/mol is the energy released when atom attaches electron to create negative ion. Cl(g) + e- Cl-(g) ∆ E = - 349 kJ/mol Chapter 7. Properties of elements Chapter Trends in electron affinities Basic properties Chapter 7. Properties of elements Chapter Basic properties Electronic structure in chemical analysis Flame atomic emission: Different orbital energy levels of different elements reveal themselves in the excitation/emission in flame. Chapter 7. Properties of elements Chapter Group 1A – Alkali metals Chapter 7. Properties of elements Chapter Group 2A – Alkaline earth metals Chapter 7. Properties of elements Chapter Group 4A – carbon, silicon, … Chapter 7. Properties of elements Chapter Groups 1B to 8B – transition metals ...
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This note was uploaded on 01/02/2012 for the course CHEM 114 taught by Professor Sergeiaksyonov during the Fall '11 term at ASU.

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