11) In extrinsic semiconductors, the band width is set by the element and cannot be changed. 12) The description of covalent bond formation as a region of high electronic charge density resulting from overlap of atomic orbitals between the two bonded atoms is referred to as: A) atomic orbital theory B) the electron-sea model C) hybridization theory D) valence-bond method E) VSEPR method 13) Which of the following statements concerning the carbon dioxide molecule is correct? A) The molecule contains two lone pairs of valence electrons. B) The molecule contains two σ bonds. C) The molecule contains four π bonds. D) The carbon is described by sp2 hybridization. E) Each oxygen is described by sp3 hybridization. 14) Which statement regarding VB theory is INCORRECT? A) d orbitals are not included in hybrid orbitals. B) Hybrid orbitals use atomic orbitals from the outermost shell. C) Sigma bonds are end-to-end overlaps. D) Pi bonds are overlaps of parallel p orbitals. E) A double bond is a sigma bond and a pi bond. 15) According to the principles of VSEPR applied on ICl5, which of the following is INCORRECT? A) VSEPR formula = AX5E B) molecular geometry = square pyramid C) hybridization = sp3d D) electron pair geometry = octahedral E) one lone pair and 5 bonding pairs 16) According to principles of VSEPR theory applied on AsCl52-, which of the following is INCORRECT? A) VSEPR formula = AX5E B) molecular geometry = square planar C) electron pair geometry = octahedral D) hybridization = sp3d2 E) one lone pair and 5 bonding pairs 17) Which statement is INCORRECT? A) The bond length is the internuclear distance. B) The covalent bond is a region of high electron charge density between two atoms. C) Hybrid orbitals are combinations of atomic orbitals. D) There are the same number of hybrid orbitals produced as the number of atomic orbitals combined. E) An sp hybridization produces a tetrahedral molecule. 18) Which statement is correct for the structure shown? A) Carbon no. 1 is described by sp3 hybridization. B) The molecule contains 19 σ bonds. C) Carbon no. 2 is described by sp2 hybridization. D) The molecule contains a total of five π bonds. E) Carbon no. 7 is described by sp hybridization. 19) Which of the pairs of molecules below have the same hybridization on the central atom? (The central atom is underlined.) A) HOCl, ClF3 B) H2O, HNO C) HCN, CO2 D) BeH2, NH3 E) H3COH, CH2O 20) Which statement is correct for the structure shown? A) The molecule contains a total of 16 σ bonds. B) Carbon no. 1 is described by sp hybridization. C) The molecule contains a total of four π bonds. D) Carbon no. 3 is described by sp3 hybridization. E) The molecule contains a delocalized π bond system.