Element 1: Hydrogen (H) / āĻŽā§ŒāϞ ā§§: āĻšāĻžāχāĻĄā§ā§°â€™āĻœā§‡āύ (H) – Used as rocket fuel, fuel cells, ammonia production.


Element 1: Hydrogen (H) / āĻŽā§ŒāϞ ā§§: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ (H)


Basic Information / āĻŽā§ŒāϞāĻŋāĻ• āϤāĻĨā§āϝ



  • Name: Hydrogen / āύāĻžāĻŽ: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ

  • Symbol: H / āϚāĻŋāĻšā§āύ: H

  • Atomic Number: 1 / āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž: ā§§

  • Nature: Non-metal (Gas) / āĻĒā§ā§°āĻ•ā§ƒāϤāĻŋ: āĻ…āϧāĻžāϤ⧁ (āϗ⧇āĻ›)


Hydrogen is the first element of the periodic table.: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻšā§ˆāϛ⧇ āĻ†ā§ąā§°ā§āϤ āϏāĻžā§°āϪ⧀⧰ āĻĒā§ā§°āĻĨāĻŽ āĻŽā§ŒāϞāĨ¤


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



  • Protons: 1 / āĻĒā§ā§°ā§‹āϟāύ: ā§§

  • Electrons: 1 / āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ: ā§§

  • Neutrons: 0 (usually) / āύāĻŋāωāĻŸā§ā§°āύ: ā§Ļ (āϏāĻžāϧāĻžā§°āĻŖāϤ⧇)


It is the simplest atom. : āχ āĻšā§ˆāϛ⧇ āφāϟāĻžāχāϤāĻ•ā§ˆ āϏāĻšāϜ āĻĒā§°āĻŽāĻžāϪ⧁āĨ¤


Properties / āϗ⧁āĻŖāϏāĻŽā§‚āĻš



  • Colorless gas / ā§°āĻ‚ āύāĻžāĻĨāĻ•āĻž āϗ⧇āĻ›

  • Lightest element / āφāϟāĻžāχāϤāĻ•ā§ˆ āĻĒā§‹āĻšā§° āĻŽā§ŒāϞ

  • Highly flammable / āϏāĻšāĻœā§‡ āĻœā§āĻŦāϞāĻŋ āωāϠ⧇

  • Exists as H₂ molecule / H₂ āĻ…āϪ⧁ āĻšāĻŋāϚāĻžāĻĒ⧇ āĻĨāĻžāϕ⧇



Occurrence / āĻ•’āϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ



  • In water (H₂O) / āĻĒāĻžāύ⧀āϤ (H₂O)

  • In Sun & stars / āĻ¸ā§‚ā§°ā§āϝ āφ⧰⧁ āϤāĻžā§°āĻžāϤ

  • Most abundant in universe / āĻŦā§ā§°āĻšā§āĻŽāĻžāĻŖā§āĻĄāϤ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻŦ⧇āĻ›āĻŋ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ


Hydrogen in Water / āĻĒāĻžāύ⧀āϤ āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ


Water formula = H₂O :- 2 Hydrogen + 1 Oxygen : ⧍āϟāĻž āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ + ā§§āϟāĻž āĻ…āĻ•ā§āϏāĻŋāĻœā§‡āύ


Uses / āĻŦā§āĻ¯ā§ąāĻšāĻžā§°



  • Fuel (rocket) / āχāĻ¨ā§āϧāύ (ā§°āϕ⧇āϟāϤ

  • Fuel cells / āĻŦāĻŋāĻĻā§āĻ¯ā§ā§Ž āĻ‰ā§ŽāĻĒāĻžāĻĻāύāϤ

  • Industries / āωāĻĻā§āϝ⧋āĻ—āϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§°


Importance / āϗ⧁⧰⧁āĻ¤ā§āĻŦ



  • Part of water (life) / āĻœā§€ā§ąāύ⧰ āĻŦāĻžāĻŦ⧇ āĻĒāĻžāύ⧀⧰ āĻ…āĻ‚āĻļ

  • Powers Sun / āĻ¸ā§‚ā§°ā§āϝāĻ• āĻļāĻ•ā§āϤāĻŋ āĻĻāĻŋāϝāĻŧ⧇

  • Clean energy source / āĻĒā§°āĻŋāĻˇā§āĻ•āĻžā§° āĻļāĻ•ā§āϤāĻŋā§° āĻ‰ā§ŽāϏ


Fun Fact  / ā§°ā§‹āĻŽāĻžāĻžā§āϚāϕ⧰ āϤāĻĨā§āϝ



  • Most of the universe is made of hydrogen. : āĻŦā§ā§°āĻšā§āĻŽāĻžāĻŖā§āĻĄā§° āĻŦ⧇āĻ›āĻŋāĻ­āĻžāĻ— āĻ…āĻ‚āĻļ āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ⧇⧰⧇ āĻ—āĻ āĻŋāϤāĨ¤


========================================================================


Hydrogen (H) – PYQ MCQs


Q1. Hydrogen is placed in which group of the periodic table ? : āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻ†ā§ąā§°ā§āϤ āϏāĻžā§°āϪ⧀⧰ āϕ⧋āύāĻŸā§‹ āĻ—ā§‹āϟāϤ āĻĨāĻžāϕ⧇ ?


(a) Group 1  (b) Group 17   (c) Group 18   (d) Group 2


Ans: (a) Group 1
Explanation: Hydrogen is placed in Group 1 due to its 1 electron. :āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ⧰ ā§§āϟāĻž āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻĨāĻ•āĻžā§° āĻŦāĻžāĻŦ⧇ āχ āĻ—ā§‹āϟ ā§§āϤ ā§°āĻ–āĻž āĻšā§ˆāϛ⧇āĨ¤


Q2. Atomic number of hydrogen is: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ⧰ āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž āĻ•āĻŋ ?


(a) 2  (b) 1  (c) 3  (d) 0


Ans: (b) 1
Explanation: It has 1 proton. : āĻ‡ā§ŸāĻžāϤ ā§§āϟāĻž āĻĒā§ā§°ā§‹āϟāύ āĻĨāĻžāϕ⧇āĨ¤


Q3. Hydrogen exists as: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āϕ⧇āύ⧇āĻ•ā§ˆ āĻĨāĻžāϕ⧇ ?


(a) H   (b) H₂  (c) H₃   (d) H₂O


Ans: (b) H₂
Explanation: Hydrogen is a diatomic molecule. : āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻĻ⧁āϟāĻž āĻĒā§°āĻŽāĻžāϪ⧁⧰⧇ āĻ—āĻ āĻŋāϤ āĻ…āϪ⧁āĨ¤


Q4. Which of the following is a property of hydrogen ? āϤāϞ⧰ āϕ⧋āύāĻŸā§‹ āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ⧰ āϗ⧁āĻŖ ?


(a) Heavy gas  (b) Colored gas  (c) Lightest element   (d) Solid


Ans: (c) Lightest element


Explanation: Hydrogen is the lightest element. : āχ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻĒā§‹āĻšā§° āĻŽā§ŒāϞāĨ¤


Q5. Hydrogen is mainly found in: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻŽā§āĻ–ā§āϝāϤ āĻ•’āϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ ?


(a) Soil   (b) Water   (c) Rocks   (d) Metals


Ans: (b) Water
Explanation: Hydrogen is part of water (H₂O). : āĻĒāĻžāύ⧀⧰ āĻ…āĻ‚āĻļ āĻšāĻŋāϚāĻžāĻĒ⧇ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤


Q6. Hydrogen is classified as: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύāĻ• 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: (b) Non-metal
Explanation: Hydrogen is a non-metal gas. : āχ āĻ…āϧāĻžāϤ⧁ āϗ⧇āĻ›āĨ¤


Q7. How many electrons are present in hydrogen atom ? āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻĒā§°āĻŽāĻžāϪ⧁āϤ āĻ•āĻŋāĻŽāĻžāύ āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻĨāĻžāϕ⧇ ?


(a) 2  (b) 1   (c) 0   (d) 3


Ans: (b) 1
Explanation: Hydrogen has 1 electron. : āĻ‡ā§ŸāĻžāϤ ā§§āϟāĻž āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻĨāĻžāϕ⧇āĨ¤


Q8. Hydrogen is used as: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āĻ•āĻŋāĻšā§° āĻŦāĻžāĻŦ⧇ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ ?


(a) Fuel  (b) Plastic  (c) Salt  (d) Glass


Ans: (a) Fuel
Explanation: Hydrogen is used as a fuel. : āχ āχāĻ¨ā§āϧāύ āĻšāĻŋāϚāĻžāĻĒ⧇ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤


Q9. Which element combines with hydrogen to form water ? : āĻĒāĻžāύ⧀ āĻ—āĻ āύ āϕ⧰āĻŋāĻŦāϞ⧈ āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ⧇ āϕ⧋āύāĻŸā§‹ āĻŽā§ŒāϞ⧰ āϏ⧈āϤ⧇ āϝ⧁āĻ•ā§āϤ āĻšāϝāĻŧ ?


(a) Nitrogen  (b) Oxygen   (c) Carbon   (d) Helium


Ans: (b) Oxygen
Explanation: Water = H₂O. : āĻĒāĻžāύ⧀ = H₂OāĨ¤


Q10. Hydrogen is most abundant in: āĻšāĻžāχāĻĄā§ā§°’āĻœā§‡āύ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻŦ⧇āĻ›āĻŋ āĻ•’āϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ ?


(a) Earth  (b) Ocean   (c) Universe   (d) Air


Ans: (c) Universe
Explanation: Most of the universe is hydrogen. : āĻŦā§ā§°āĻšā§āĻŽāĻžāĻŖā§āĻĄāϤ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻŦ⧇āĻ›āĻŋ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤