Ionization Energies; Electron Affinities (Sections)f the

Elementary Chemistry Ch 4.3­4.8 4.3 Quantum Numbers  Each electron in an atom is associated with a set of four Quantum Numbers  Principle Quantum Number (n): o Any positive integral value  Most stable atoms have values from 1­7  Ground State: most stable electronic state of an atom  Excited State: any state higher than the ground state  Angular Momentum Quantum Number (ℓ): o Electrons have values from zero ­ (n­1)  Cannot be as large as n o Small role in determining the energy of the electron o Determines the shape of the volume of space that the electron can occupy  Magnetic Quantum Number (m ): e o Values ranging from ­ℓ through xero to +e o Value of m eoesn't normally affect the energy of an electron o Determines the orientation in space of the volume that can contain the electron  Spin Quantum Number (m ): s o Values of ­½ or +½ o Value doesn't depend on value of any other quantum number o Gives the orientation of the magnetic field associated with the electron  Pauli Exclusion Principle: no two electrons in an atom can have the same set of four quantum numbers o Together with the n+e rule, it determines the number of electrons in an atom 4.4 Relative Energies of Electrons  N+e rule: Electrons increase in energy as the sum of n+e increases o Can make a