What observation led Neil Bartlett to try reacting xenon with PtF₆ in 1962?
AXenon had already been shown to react with fluorine gas
BPtF₆ oxidizes O₂ to O₂⁺, and the first ionization energy of O₂ is close to that of xenon
CXenon has a lower electronegativity than any metal
DPtF₆ is a strong reducing agent
Bartlett had made O₂⁺[PtF₆]⁻. Noting that xenon's first ionization energy is almost the same as that of O₂, he reasoned PtF₆ should oxidize xenon too, and it did.
Question 2 Multiple Choice
What is the molecular shape of XeF₄?
ATetrahedral
BSeesaw
CSquare planar
DSquare pyramidal
Xenon has four bonding pairs and two lone pairs, an octahedral electron arrangement. The lone pairs sit opposite each other, leaving the four fluorines in a square plane.
Question 3 True / False
Bonding in XeF₂ requires the participation of xenon's 5d orbitals.
TTrue
FFalse
Answer: False
The linear F–Xe–F unit is well described by a three-center four-electron bond made from a xenon 5p orbital and one p orbital on each fluorine. Two electrons fill a bonding orbital and two fill a nonbonding orbital located mostly on the fluorines.
Question 4 Short Answer
Why does xenon form compounds much more readily than argon?
Think about your answer, then reveal below.
Model answer: Xenon has a much lower ionization energy and a larger, more polarizable electron cloud, so very electronegative partners like fluorine and oxygen can draw electron density from it. Argon holds its electrons too tightly.
Ionization energy falls down group 18. This is the same trend that made Bartlett's comparison with O₂ work for xenon but not for the lighter noble gases.