32. What is the point group for 1,3,5,7-cyclooctatetraene (COT)? (A) C₂ₕ (B) S₄ (C) D₄ₕ (D) D₂d (E) C₂ᵥ

4. Both ZnS and CaF₂ have a face-centered cubic unit cell where the S²⁻ and Ca²⁺ ions are closest packed in each structure. Which of the following is true? (A) There are 4 tetrahedral holes empty in each structure. (B) In both compounds, one-half of the tetrahedral holes are filled. (C) In both compounds, all the tetrahedral holes are filled. (D) There are 8 Zn²⁺ ions and 4 F⁻ ions in the unit cell. (E) In ZnS, one-half of the tetrahedral holes are filled by Zn²⁺ ions, whereas in CaF₂ all the tetrahedral holes are filled with F⁻ ions.

32. What is the point group for 1,3,5,7-cyclooctatetraene (COT)?

(A) C₂ₕ
(B) S₄
(C) D₄ₕ
(D) D₂d
(E) C₂ᵥ

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