Element 5: Boron (B) / āĻŽā§ŒāϞ ā§Ģ: āĻŦā§°āĻŖ (B) – Used in glass, detergents, fertilizers.


Basic Information / āĻŽā§ŒāϞāĻŋāĻ• āϤāĻĨā§āϝ



  • Name: Boron / āύāĻžāĻŽ: āĻŦā§°āĻŖ

  • Symbol: B / āϚāĻŋāĻšā§āύ: B

  • Atomic Number: 5 / āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž: ā§Ģ

  • Nature: Metalloid / āĻĒā§ā§°āĻ•ā§ƒāϤāĻŋ: āωāĻĒāϧāĻžāϤ⧁


Boron is a metalloid (between metal and non-metal). : āĻŦā§°āĻŖ āĻāϟāĻž āωāĻĒāϧāĻžāϤ⧁ (āϧāĻžāϤ⧁ āφ⧰⧁ āĻ…āϧāĻžāϤ⧁⧰ āĻŽāĻžāϜāϤ)āĨ¤


Structure of Atom / āĻĒā§°āĻŽāĻžāϪ⧁⧰ āĻ—āĻ āύ



  • Protons: 5 / āĻĒā§ā§°ā§‹āϟāύ: ā§Ģ

  • Electrons: 5 / āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ: ā§Ģ

  • Neutrons: 6 (usually) / āύāĻŋāωāĻŸā§ā§°āύ: ā§Ŧ (āϏāĻžāϧāĻžā§°āĻŖāϤ⧇)


Simple atomic structure. : āϏāĻšāϜ āĻĒā§°āĻŽāĻžāϪ⧁ āĻ—āĻ āύāĨ¤


Properties / āϗ⧁āĻŖāϏāĻŽā§‚āĻš



  • Hard and strong / āĻ•āĻ āĻŋāύ āφ⧰⧁ āĻļāĻ•ā§āϤāĻŋāĻļāĻžāϞ⧀

  • Not purely metal or non-metal / āϏāĻŽā§āĻĒā§‚ā§°ā§āĻŖ āϧāĻžāϤ⧁ āύāĻšāϝāĻŧ āĻŦāĻž āĻ…āϧāĻžāϤ⧁āĻ“ āύāĻšāϝāĻŧ

  • Heat resistant / āϤāĻžāĻĒ āϏāĻšāύāĻļā§€āϞ

  • Semiconducting nature / āĻ…ā§°ā§āϧ-āĻŦāĻŋāĻĻā§āĻ¯ā§ā§Ž āĻĒā§°āĻŋāĻŦāĻžāĻšā§€ āϗ⧁āĻŖ


Uses / āĻŦā§āĻ¯ā§ąāĻšāĻžā§°



  • Glass making (borosilicate glass) / āĻ—ā§āϞāĻžāĻ› āĻŦāĻ¨ā§‹ā§ąāĻžāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§°

  • Detergents / āĻĄāĻŋāϟāĻžā§°ā§āĻœā§‡āĻ¨ā§āϟāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§°

  • Fiberglass / āĻĢāĻžāχāĻŦāĻžā§°āĻ—ā§āϞāĻžāĻ›āϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§°


Importance / āϗ⧁⧰⧁āĻ¤ā§āĻŦ



  • Makes heat-resistant glass

  • Important for cleaning products

  • Used in strong lightweight materials


Why is Boron Special ? / āĻ•āĻŋāϝāĻŧ āĻŦā§°āĻŖ āĻŦāĻŋāĻļ⧇āώ ?


It is a metalloid, so it shows properties of both metals and non-metals. : āχ āωāĻĒāϧāĻžāϤ⧁, āϏ⧇āϝāĻŧ⧇ āϧāĻžāϤ⧁ āφ⧰⧁ āĻ…āϧāĻžāϤ⧁⧰ āĻĻ⧁āϝāĻŧā§‹āϟāĻž āϗ⧁āĻŖ āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤


Fact / āϤāĻĨā§āϝ : Boron helps make heat-resistant glass. : āĻŦā§°āϪ⧇ āϤāĻžāĻĒ-āϏāĻšāύāĻļā§€āϞ āĻ—ā§āϞāĻžāĻ› āĻŦāĻ¨ā§‹ā§ąāĻžāϤ āϏāĻšāĻžāϝāĻŧ āϕ⧰⧇āĨ¤


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Boron (B) – PYQ MCQs


Q1. Boron belongs to which group of the periodic table ? āĻŦā§°āĻŖ āĻ†ā§ąā§°ā§āϤ āϏāĻžā§°āϪ⧀⧰ āϕ⧋āύāĻŸā§‹ āĻ—ā§‹āϟāϤ āĻĒ⧰⧇ ?
(a) Group 13 (b) Group 2 (c) Group 1 (d) Group 18


Ans: (a) Group 13
Explanation: Boron is placed in Group 13 of the periodic table. : āĻŦā§°āĻŖ āĻ†ā§ąā§°ā§āϤ āϏāĻžā§°āϪ⧀⧰ āĻ—ā§‹āϟ ā§§ā§ŠāϤ āĻĨāĻžāϕ⧇āĨ¤


Q2. Atomic number of boron is: āĻŦā§°āĻŖā§° āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž āĻ•āĻŋ ?
(a) 3 (b) 4 (c) 5 (d) 6


Ans: (c) 5
Explanation: Atomic number = number of protons = 5. : āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž = āĻĒā§ā§°ā§‹āϟāύ⧰ āϏāĻ‚āĻ–ā§āϝāĻž = ā§ĢāĨ¤


Q3. Boron is classified as: āĻŦā§°āĻŖāĻ• āϕ⧇āύ⧇āĻ•ā§ˆ āĻļā§ā§°ā§‡āĻŖā§€āĻŦāĻĻā§āϧ āϕ⧰āĻž āĻšāϝāĻŧ ?
(a) Metal (b) Non-metal (c) Metalloid (d) Noble gas


Ans: (c) Metalloid
Explanation: Boron shows properties of both metals and non-metals. : āĻŦā§°āĻŖ āϧāĻžāϤ⧁ āφ⧰⧁ āĻ…āϧāĻžāϤ⧁⧰ āĻĻ⧁āϝāĻŧā§‹āϟāĻž āϗ⧁āĻŖ āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤


Q4. Number of electrons in boron atom is: āĻŦā§°āĻŖ āĻĒā§°āĻŽāĻžāϪ⧁āϤ āĻ•āĻŋāĻŽāĻžāύ āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻĨāĻžāϕ⧇ ?
(a) 3 (b) 4 (c) 5 (d) 6


Ans: (c) 5
Explanation: Electrons = atomic number = 5. : āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ = ā§ĢāĨ¤


Q5. Boron is mainly used in: āĻŦā§°āĻŖ āĻŽā§āĻ–ā§āϝāϤ āĻ•’āϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ ?
(a) Food (b) Glass (c) Paper (d) Fuel


Ans: (b) Glass
Explanation: Boron is used to make borosilicate glass. : āĻŦā§°āĻŖ āĻ—ā§āϞāĻžāĻ› āĻŦāĻ¨ā§‹ā§ąāĻžāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤


Q6. Boron compounds are used in: āĻŦā§°āĻŖā§° āϝ⧌āĻ— āĻ•’āϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ ?
(a) Detergents (b) Wood (c) Plastic (d) Fuel


Ans: (a) Detergents
Explanation: Boron compounds are used in detergents. : āĻĄāĻŋāϟāĻžā§°ā§āĻœā§‡āĻ¨ā§āϟāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤


Q7. Boron is: āĻŦā§°āĻŖ āĻšā§ˆāϛ⧇ -
(a) Soft metal (b) Hard element (c) Gas (d) Liquid


Ans: (b) Hard element
Explanation: Boron is hard and strong. : āĻŦā§°āĻŖ āĻ•āĻ āĻŋāύ āφ⧰⧁ āĻļāĻ•ā§āϤāĻŋāĻļāĻžāϞ⧀āĨ¤


Q8. How many protons are present in boron ? : āĻŦā§°āĻŖāϤ āĻ•āĻŋāĻŽāĻžāύ āĻĒā§ā§°ā§‹āϟāύ āĻĨāĻžāϕ⧇ ?
(a) 3 (b) 4 (c) 5 (d) 6


Ans: (c) 5
Explanation: Protons = atomic number = 5. āĻĒā§ā§°ā§‹āϟāύ = ā§ĢāĨ¤


Q9. Boron is important in fiberglass because: āĻŦā§°āĻŖ āĻĢāĻžāχāĻŦāĻžā§°āĻ—ā§āϞāĻžāĻ›āϤ āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚āĻ°ā§āĻŖ āĻ•āĻžā§°āĻŖ -
(a) It is weak (b) It adds strength (c) It is gas (d) It is heavy


Ans: (b) It adds strength
Explanation: Boron makes fiberglass strong and durable. : āχ āĻĢāĻžāχāĻŦāĻžā§°āĻ—ā§āϞāĻžāĻ›āĻ• āĻļāĻ•ā§āϤāĻŋāĻļāĻžāϞ⧀ āϕ⧰⧇āĨ¤


Q10. Boron helps in making: : āĻŦā§°āĻŖ āĻ•āĻŋāĻš āĻŦāĻ¨ā§‹ā§ąāĻžāϤ āϏāĻšāĻžāϝāĻŧ āϕ⧰⧇?
(a) Soft glass (b) Heat-resistant glass (c) Water (d) Fuel


Ans: (b) Heat-resistant glass


Explanation: Boron is used to make heat-resistant glass. : āχ āϤāĻžāĻĒ-āϏāĻšāύāĻļā§€āϞ āĻ—ā§āϞāĻžāĻ› āĻŦāĻ¨ā§‹ā§ąāĻžāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤