9. What is the symmetry of the following ligand group orbital (LGO) in a D₄ₕ point group?(A) A₁g (B) A₂u (C) Eu (D) A₁u (E) A₂g

1. The Nobel Prize in Chemistry in 2022 was awarded to click chemistry, or the azide-alkyne cycloaddition to connect two molecular fragments. For their initial discovery, what metal ion was required as a catalyst for this reaction to proceed at a milder condition? (A) Cu(I) (B) Zn(II) (C) Fe(II) (D) Fe(III) (E) Mo(II)