Second Electron Shell 2p node clectron density node node electron distance from density the nucleus distance distance from the from the nucleus nucleus nucleus nucleus node nodal plane Cooyright 2005 Pearson Prentice Hall,ing 2s orbital (spherical) => 2p orbital Chapter 1 Three p orbitals 6
Chapter 1 6 Second Electron Shell 2s orbital (spherical) => Three p orbitals 2p orbital
Electronic Configurations ·Aufbau Principle: Place electrons in Relative orbital energies lowest energy 12p.↑2p,-2p. orbital first. ·Hund's Rule: energy ￥2s Equal energy orbitals are half- filled,then filled. Copyright2005 Pearson Prentice Hall,Inc. ·6C:1s22s22p2 二> Chapter 1
Chapter 1 7 Electronic Configurations • Aufbau Principle: Place electrons in lowest energy orbital first. • Hund’s Rule: Equal energy orbitals are halffilled, then filled. • 6C: 1s 2 2s 2 2p 2 =>
Electronic Configurations TABLE 1-1 Electronlc Conflguratlons of the Elements of the FIrst and Second Rows Element Configuration Valence Electrons H 1s1 1 He 1s2 2 Li 1522s1 Be 1s22x2 2 B 1s2222p 3 C 1s22s22p2p 4 N 1s22522p12p2p 5 0 1s22s22p22p2p 6 F 1s22s22p22p2p 7 Ne 1s22s22p22p2p月 8 => Chapter 1
Chapter 1 8 Electronic Configurations =>
Bond Formation lonic bonding:electrons are transferred. Covalent bonding:electron pair is shared. HO:H -C Na+:CI nonpolar polar ionic bond covalent bond covalent bond Copyright2005 Pearson Prentice Hall.Inc. => Chapter 1 9
Chapter 1 9 Bond Formation • Ionic bonding: electrons are transferred. • Covalent bonding: electron pair is shared. =>
Lewis Structures ·Bonding electrons Nonbonding electrons or lone pairs H H Satisfy the octet rule! => Chapter 1 10
Chapter 1 10 Lewis Structures • Bonding electrons • Nonbonding electrons or lone pairs Satisfy the octet rule! => C H H H O H