✅ What is Xenon?

Xenon is a chemical element belonging to the noble gases group of the periodic table. It is a rare, heavy, colorless, and odorless gas known for its chemical inertness. Despite being largely unreactive, xenon can form compounds under special conditions.

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✅ Detailed Information about Xenon (Competitive Exam Focus)

Symbol: Xe
Atomic Number: 54
Atomic Mass: ~131.29 u
Electronic Configuration: [Kr] 4d¹⁰ 5s² 5p⁶
Group: 18 (Noble Gases)
Period: 5

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🔹 Occurrence

• Xenon is extremely rare in the Earth’s atmosphere (about 0.0000087% by volume).

• Commercially obtained by fractional distillation of liquid air.

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🔹 Physical Properties

• State: Gas (under standard conditions)

• Color: Colorless

• Odor: Odorless

• Density: ~5.9 kg/m³ (heavier than air)

• Melting Point: −111.8 °C

• Boiling Point: −108.1 °C

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🔹 Chemical Properties

• Inert Nature: Like other noble gases, xenon is generally chemically unreactive.

• Reactivity: Under special conditions (high pressure, presence of fluorine), xenon forms compounds.

• Important Compounds:

  • Xenon Difluoride (XeF₂)

  • Xenon Tetrafluoride (XeF₄)

  • Xenon Hexafluoride (XeF₆)

  • Xenon Oxytetrafluoride (XeOF₄)

  • Xenon trioxide (XeO₃)

Note: The discovery of xenon compounds in the 20th century disproved the belief that noble gases are entirely inert.

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🔹 Discovery

• Discovered in 1898 by William Ramsay and Morris Travers in London.

• They identified xenon while studying residues left after evaporating liquid air.

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🔹 Uses and Applications

• Lighting:

  • Xenon arc lamps (used in cinema projectors, searchlights)

  • Xenon flash lamps (photography)

  • High-intensity automobile headlights

• Medical:

  • Used as a general anesthetic (has minimal side effects)

  • Radioactive isotopes of xenon used in imaging and diagnostics

• Space Technology:

  • Ion propulsion systems (xenon gas is used as propellant in spacecraft thrusters)

• Nuclear Monitoring:

  • Certain isotopes are used for detecting nuclear explosions

1. Who discovered xenon?
a) Henry Cavendish
b) Humphry Davy
c) William Ramsay and Morris Travers
d) Antoine Lavoisier

Answer: c) William Ramsay and Morris Travers

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2. Xenon is used as a propellant in which of the following?
a) Solid fuel rockets
b) Ion propulsion systems
c) Liquid fuel engines
d) Hybrid engines

Answer: b) Ion propulsion systems

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3. Which of the following xenon compounds was the first noble gas compound discovered?
a) XeF₂
b) XeF₄
c) XePtF₆
d) XeO₃

Answer: c) XePtF₆

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4. The percentage of xenon in Earth’s atmosphere by volume is approximately:
a) 0.1%
b) 0.01%
c) 0.0009%
d) 0.0000087%

Answer: d) 0.0000087%

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5. Xenon belongs to which group of the periodic table?
a) Group 16
b) Group 17
c) Group 18
d) Group 1

Answer: c) Group 18

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6. Which of the following statements about xenon is incorrect?
a) Xenon is heavier than air.
b) Xenon is completely inert and does not form any compounds.
c) Xenon is used in anesthesia.
d) Xenon can form fluorides under special conditions.

Answer: b) Xenon is completely inert and does not form any compounds.

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7. Xenon difluoride (XeF₂) is an example of:
a) An oxide
b) A fluoride
c) A chloride
d) A sulfide

Answer: b) A fluoride

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✅ Comparison with Other Noble Gases

Property	Helium (He)	Neon (Ne)	Argon (Ar)	Krypton (Kr)	Xenon (Xe)
Atomic Number	2	10	18	36	54
Density (g/L)	0.1786	0.9002	1.784	3.749	5.894
Reactivity	Extremely inert	Inert	Inert	Slightly reactive	More reactive (forms compounds)
Occurrence in atmosphere	~5.2 ppm	~18 ppm	~9340 ppm	~1 ppm	~0.087 ppm
Boiling Point (°C)	−268.9	−246.0	−185.8	−153.2	−108.1

Note: Xenon is the most reactive of the heavier noble gases and forms the most compounds among them.

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✅ Important Xenon Compounds

Here are some xenon compounds, which often get asked in exams:

🔹 Xenon Difluoride (XeF₂)

• Colorless crystalline solid

• Used as a fluorinating agent

🔹 Xenon Tetrafluoride (XeF₄)

• First binary noble gas compound to be synthesized

• Stable, white solid

🔹 Xenon Hexafluoride (XeF₆)

• Highly reactive

• Strong fluorinating agent

🔹 Xenon Hexafluoroplatinate (XePtF₆)

• First noble gas compound discovered

• Formed by reaction of xenon and platinum hexafluoride

🔹 Xenon trioxide (XeO₃)

• Powerful oxidizing agent

• Explosive in dry state