Element 9: Fluorine (F) / āĻŽā§āϞ ⧝: āĻĢā§āϞā§ā§°āĻŋāύ (F) â Used in toothpaste, Teflon, refrigerants.
Basic Information / āĻŽā§āϞāĻŋāĻ āϤāĻĨā§āϝ
- Name: Fluorine / āύāĻžāĻŽ: āĻĢā§āϞā§ā§°āĻŋāύ
- Symbol: F / āĻāĻŋāĻšā§āύ: F
- Atomic Number: 9 / āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āϏāĻāĻā§āϝāĻž: ⧝
- Nature: Non-metal (Gas) / āĻĒā§ā§°āĻā§āϤāĻŋ: āĻ āϧāĻžāϤ⧠(āĻā§āĻ)
Fluorine is the most reactive non-metal. : āĻĢā§āϞā§ā§°āĻŋāύ āĻšā§āĻā§ āĻāĻāĻžāĻāϤāĻā§ āϏāĻā§ā§°āĻŋāϝāĻŧ āĻ
āϧāĻžāϤā§āĨ¤
Structure of Atom / āĻĒā§°āĻŽāĻžāĻŖā§ā§° āĻāĻ āύ
- Protons: 9 / āĻĒā§ā§°ā§āĻāύ: ⧝
- Electrons: 9 / āĻāϞā§āĻā§āĻā§ā§°āύ: ⧝
- Neutrons: 10 (usually) / āύāĻŋāĻāĻā§ā§°āύ: ā§§ā§Ļ (āϏāĻžāϧāĻžā§°āĻŖāϤā§)
Electronic configuration: 2, 7 : āĻāϞā§āĻā§āĻā§ā§°āύ āĻŦāĻŋāύā§āϝāĻžāϏ: 2, 7
Properties / āĻā§āĻŖāϏāĻŽā§āĻš
- Pale yellow gas / āĻšāĻžāϞāϧā§āϝāĻŧāĻž ā§°āĻā§° āĻā§āĻ
- Highly reactive / āĻŦāĻšā§āϤ āϏāĻā§ā§°āĻŋāϝāĻŧ
- Does not exist freely / āĻāĻā§āϞāĻā§ āĻĒā§ā§ąāĻž āύāĻžāϝāĻžāϝāĻŧ
- Exists as Fâ molecule / Fâ āĻ āĻŖā§ āĻšāĻŋāĻāĻžāĻĒā§ āĻĨāĻžāĻā§
Occurrence / āĻ’āϤ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧ
- Found in compounds (fluorides)
- Not found freely in nature : āĻĒā§ā§°āĻžāĻā§āϤāĻŋāĻ āĻ ā§ąāϏā§āĻĨāĻžāϤ āĻāĻā§āϞāĻā§ āύāĻžāĻĨāĻžāĻā§āĨ¤
Uses / āĻŦā§āĻ¯ā§ąāĻšāĻžā§°
- Toothpaste (fluoride) / āĻĻāĻžāĻāϤ⧰ āĻĒā§āώā§āĻāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ
- Chemicals / ā§°āĻžāϏāĻžāϝāĻŧāύāĻŋāĻ āĻĒāĻĻāĻžā§°ā§āĻĨ āϤā§āϝāĻŧāĻžā§°āϤ
- Protects teeth / āĻĻāĻžāĻāϤ ā§°āĻā§āώāĻž āĻā§°ā§
Importance / āĻā§ā§°ā§āϤā§āĻŦ
- Prevents tooth decay / āĻĻāĻžāĻāϤ⧰ āĻā§āώāϝāĻŧ ā§°ā§āϧ āĻā§°ā§
- Used in industrial chemicals
- Important in chemical reactions
Why is Fluorine So Reactive ? / āĻāĻŋāϝāĻŧ āĻĢā§āϞā§ā§°āĻŋāύ āĻŦāĻšā§āϤ āϏāĻā§ā§°āĻŋāϝāĻŧ ?
- It needs 1 electron to complete its outer shell. : āĻāϝāĻŧāĻžāĻ āĻŦāĻžāĻšā§āϝāĻŋāĻ āĻā§āϞ āĻĒā§ā§°āĻŖ āĻā§°āĻŋāĻŦāϞ⧠⧧āĻāĻž āĻāϞā§āĻā§āĻā§ā§°āύ āϞāĻžāĻā§āĨ¤
- So it reacts very quickly. : āϏā§āϝāĻŧā§ āĻ āϤā§āĻā§āώāĻŖāĻžāϤ āĻŦāĻŋāĻā§ā§°āĻŋāϝāĻŧāĻž āĻā§°ā§āĨ¤
Fact / āϤāĻĨā§āϝ : Fluoride helps prevent tooth decay. : āĻĢā§āϞā§ā§°āĻžāĻāĻĄā§ āĻĻāĻžāĻāϤ⧰ āĻā§āώāϝāĻŧ ā§°ā§āϧ āĻā§°ā§āĨ¤
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Fluorine (F) – PYQ MCQs
Q1. Fluorine belongs to which group of the periodic table ? : āĻĢā§āϞā§ā§°āĻŋāύ āĻā§ąā§°ā§āϤ āϏāĻžā§°āĻŖā§ā§° āĻā§āύāĻā§ āĻā§āĻāϤ āĻĒā§°ā§ ?
(a) Group 16 (b) Group 17 (c) Group 18 (d) Group 15
Ans: (b) Group 17
Explanation: Fluorine is a halogen, placed in Group 17. : āĻĢā§āϞā§ā§°āĻŋāύ āĻāĻāĻž āĻšā§āϞ’āĻā§āύ, āϏā§āϝāĻŧā§ āĻā§āĻ ā§§ā§āϤ āĻĨāĻžāĻā§āĨ¤
Q2. Atomic number of fluorine is: āĻĢā§āϞā§ā§°āĻŋāύ⧰ āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āϏāĻāĻā§āϝāĻž āĻāĻŋ ?
(a) 7 (b) 8 (c) 9 (d) 10
Ans: (c) 9
Explanation: Atomic number = number of protons = 9. : āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āϏāĻāĻā§āϝāĻž = āĻĒā§ā§°ā§āĻāύ⧰ āϏāĻāĻā§āϝāĻž = ⧝āĨ¤
Q3. Fluorine is classified as: āĻĢā§āϞā§ā§°āĻŋāύāĻ āĻā§āύā§āĻā§ āĻļā§ā§°ā§āĻŖā§āĻŦāĻĻā§āϧ āĻā§°āĻž āĻšāϝāĻŧ ?
(a) Metal (b) Non-metal (c) Metalloid (d) Noble gas
Ans: (b) Non-metal
Explanation: Fluorine is a non-metal gas. : āĻĢā§āϞā§ā§°āĻŋāύ āĻāĻāĻž āĻ
āϧāĻžāϤ⧠āĻā§āĻāĨ¤
Q4. Fluorine is the ______ non-metal. : āĻĢā§āϞā§ā§°āĻŋāύ āĻšā§āĻā§ ______ āĻ
āϧāĻžāϤā§āĨ¤
(a) Least reactive (b) Most reactive (c) Heaviest (d) Softest
Ans: (b) Most reactive
Explanation: Fluorine is the most reactive non-metal. : āĻĢā§āϞā§ā§°āĻŋāύ āĻāĻāĻžāĻāϤāĻā§ āϏāĻā§ā§°āĻŋāϝāĻŧ āĻ
āϧāĻžāϤā§āĨ¤
Q5. Fluorine exists as: āĻĢā§āϞā§ā§°āĻŋāύ āĻā§āύā§āĻā§ āĻĨāĻžāĻā§ ?
(a) F (b) Fâ (c) Fâ (d) HF
Ans: (b) Fâ
Explanation: Fluorine exists as a diatomic molecule. : āĻĻā§āĻāĻž āĻĒā§°āĻŽāĻžāĻŖā§ā§°ā§ āĻāĻ āĻŋāϤ (Fâ)āĨ¤
Q6. Fluorine is used in: āĻĢā§āϞā§ā§°āĻŋāύ āĻ’āϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ ?
(a) Glass (b) Toothpaste (c) Wood (d) Cement
Ans: (b) Toothpaste
Explanation: Fluoride compounds are used in toothpaste. : āĻĻāĻžāĻāϤ⧰ āĻĒā§āώā§āĻāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤
Q7. Fluorine does not exist freely because: āĻĢā§āϞā§ā§°āĻŋāύ āĻāĻā§āϞāĻā§ āύāĻžāĻĨāĻžāĻā§ āĻāĻžā§°āĻŖ -
(a) It is heavy (b) It is very reactive (c) It is solid (d) It is metal
Ans: (b) It is very reactive
Explanation: It reacts quickly with other elements. : āĻ āĻŦāĻšā§āϤ āĻĻā§ā§°ā§āϤ āĻŦāĻŋāĻā§ā§°āĻŋāϝāĻŧāĻž āĻā§°ā§āĨ¤
Q8. Number of electrons in fluorine atom is: āĻĢā§āϞā§ā§°āĻŋāύ āĻĒā§°āĻŽāĻžāĻŖā§āϤ āĻāĻŋāĻŽāĻžāύ āĻāϞā§āĻā§āĻā§ā§°āύ āĻĨāĻžāĻā§ ?
(a) 7 (b) 8 (c) 9 (d) 10
Ans: (c) 9
Explanation: Electrons = atomic number = 9. : āĻāϞā§āĻā§āĻā§ā§°āύ = ⧝āĨ¤
Q9. Fluoride helps to: āĻĢā§āϞā§ā§°āĻžāĻāĻĄā§ āĻāĻŋ āϏāĻšāĻžāϝāĻŧ āĻā§°ā§ ?
(a) Increase weight (b) Prevent tooth decay (c) Burn faster (d) Make metal
Ans: (b) Prevent tooth decay
Explanation: Fluoride protects teeth from decay. : āĻĻāĻžāĻāϤ⧰ āĻā§āώāϝāĻŧ ā§°ā§āϧ āĻā§°ā§āĨ¤
Q10. Fluorine is: āĻĢā§āϞā§ā§°āĻŋāύ āĻšā§āĻā§ -
(a) Hard solid (b) Liquid metal (c) Pale yellow gas (d) Black solid
Ans: (c) Pale yellow gas
Explanation: Fluorine is a pale yellow gas. : āĻĢā§āϞā§ā§°āĻŋāύ āĻšāĻžāϞāϧā§āϝāĻŧāĻž ā§°āĻā§° āĻā§āĻāĨ¤