Element 1: Hydrogen (H) / āĻŽā§āϞ ā§§: āĻšāĻžāĻāĻĄā§ā§°âāĻā§āύ (H) â Used as rocket fuel, fuel cells, ammonia production.
Element 1: Hydrogen (H) / āĻŽā§āϞ ā§§: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ (H)
Basic Information / āĻŽā§āϞāĻŋāĻ āϤāĻĨā§āϝ
Hydrogen (H) is the first element of the periodic table with atomic number 1. It is a non-metal gas and is known as the lightest element. āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ (H) āĻā§ąā§°ā§āϤ āϏāĻžā§°āĻŖā§ā§° āĻĒā§ā§°āĻĨāĻŽ āĻŽā§āϞ āĻā§°ā§ āĻāϝāĻŧāĻžā§° āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āϏāĻāĻā§āϝāĻž ā§§āĨ¤ āĻ āĻāĻāĻž āĻ āϧāĻžāϤ⧠āĻā§āĻ āĻā§°ā§ āĻāĻāĻžāĻāϤāĻā§ āĻĒā§āĻšā§° āĻŽā§āϞāĨ¤
Structure of Atom / āĻĒā§°āĻŽāĻžāĻŖā§ā§° āĻāĻ āύ : Hydrogen is the simplest atom, consisting of 1 proton and 1 electron, and usually no neutron, which makes its structure very basic. āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻāĻāĻžāĻāϤāĻā§ āϏāĻšāĻ āĻĒā§°āĻŽāĻžāĻŖā§, āϝ’āϤ ā§§āĻāĻž āĻĒā§ā§°ā§āĻāύ āĻā§°ā§ ā§§āĻāĻž āĻāϞā§āĻā§āĻā§ā§°āύ āĻĨāĻžāĻā§ āĻā§°ā§ āϏāĻžāϧāĻžā§°āĻŖāϤ⧠āύāĻŋāĻāĻā§ā§°āύ āύāĻžāĻĨāĻžāĻā§āĨ¤
Properties / āĻā§āĻŖāϏāĻŽā§āĻš : Hydrogen is a colorless and odorless gas that is highly flammable. It exists as a diatomic molecule (Hâ) and is the lightest element known. āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻāĻāĻž ā§°āĻ āύāĻžāĻĨāĻāĻž āĻā§°ā§ āĻāύā§āϧ āύāĻžāĻĨāĻāĻž āĻā§āĻ, āĻ āĻ āϤāĻŋ āϏāĻšāĻā§ āĻā§āĻŦāϞāĻŋ āĻāĻ ā§ āĻā§°ā§ āϏāĻžāϧāĻžā§°āĻŖāϤ⧠Hâ āĻ āĻŖā§ āĻšāĻŋāĻāĻžāĻĒā§ āĻĨāĻžāĻā§āĨ¤
Occurrence / āĻ’āϤ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧ : Hydrogen is found in water (HâO), present in the Sun and stars, and is the most abundant element in the universe. āĻ āĻĒāĻžāύ⧠(HâO), āϏā§ā§°ā§āϝ āĻā§°ā§ āϤāĻžā§°āĻžāϤ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧ āĻā§°ā§ āĻŦā§ā§°āĻšā§āĻŽāĻžāĻŖā§āĻĄāϤ āĻāĻāĻžāĻāϤāĻā§ āĻŦā§āĻāĻŋ āĻĒā§ā§ąāĻž āĻŽā§āϞāĨ¤
Hydrogen in Water / āĻĒāĻžāύā§āϤ āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ : Water is formed by 2 hydrogen atoms and 1 oxygen atom (HâO), which is essential for life on Earth. āĻĒāĻžāύ⧠⧍āĻāĻž āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻā§°ā§ ā§§āĻāĻž āĻ āĻā§āϏāĻŋāĻā§āύ (HâO)-āĻā§°ā§ āĻāĻ āĻŋāϤ āĻā§°ā§ āĻ āĻā§ā§ąāύ⧰ āĻŦāĻžāĻŦā§ āĻ āϤāĻŋ āĻĒā§ā§°āϝāĻŧā§āĻāύā§āϝāĻŧāĨ¤
Uses / āĻŦā§āĻ¯ā§ąāĻšāĻžā§°: Hydrogen is used as a fuel in rockets, in fuel cells to produce electricity, and in many industrial processes. āĻ ā§°āĻā§āĻ āĻāύā§āϧāύ, āĻŦāĻŋāĻĻā§āϝā§ā§ āĻā§āĻĒāĻžāĻĻāύ⧰ āĻŦāĻžāĻŦā§ āĻĢāĻŋāĻā§ąā§āϞ āĻā§āϞ, āĻā§°ā§ āĻŦāĻŋāĻāĻŋāύā§āύ āĻāĻĻā§āϝā§āĻāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāϝāĻŧāĨ¤
Importance / āĻā§ā§°ā§āϤā§āĻŦ : Hydrogen is important because it is part of water, helps to power the Sun, and is considered a clean source of energy for the future. āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻā§ā§°ā§āϤā§āĻŦāĻĒā§āϰā§āĻŖ āĻāĻžā§°āĻŖ āĻ āĻĒāĻžāύā§ā§° āĻ āĻāĻļ, āϏā§ā§°ā§āϝāϤ āĻļāĻā§āϤāĻŋ āĻā§āĻĒāĻžāĻĻāύ āĻā§°ā§, āĻā§°ā§ āĻāĻāĻž āĻĒā§°āĻŋāώā§āĻāĻžā§° āĻļāĻā§āϤāĻŋā§° āĻā§āϏāĨ¤
Fun Fact / ā§°ā§āĻŽāĻžāĻā§āĻāĻā§° āϤāĻĨā§āϝ: Most of the universe is made of hydrogen, making it the most common element. āĻŦā§ā§°āĻšā§āĻŽāĻžāĻŖā§āĻĄā§° āĻŦā§āĻāĻŋāĻāĻžāĻ āĻ āĻāĻļ āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύā§ā§°ā§ āĻāĻ āĻŋāϤ, āϏā§āϝāĻŧā§ āĻ āĻāĻāĻžāĻāϤāĻā§ āϏāĻžāϧāĻžā§°āĻŖ āĻŽā§āϞāĨ¤
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Hydrogen (H) – PYQ MCQs
Q1. Hydrogen is placed in which group of the periodic table ? : āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻā§ąā§°ā§āϤ āϏāĻžā§°āĻŖā§ā§° āĻā§āύāĻā§ āĻā§āĻāϤ āĻĨāĻžāĻā§ ?
(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. :āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ⧰ ā§§āĻāĻž āĻāϞā§āĻā§āĻā§ā§°āύ āĻĨāĻāĻžā§° āĻŦāĻžāĻŦā§ āĻ āĻā§āĻ ā§§āϤ ā§°āĻāĻž āĻšā§āĻā§āĨ¤
Q2. Atomic number of hydrogen is: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ⧰ āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āϏāĻāĻā§āϝāĻž āĻāĻŋ ?
(a) 2 (b) 1 (c) 3 (d) 0
Ans: (b) 1
Explanation: It has 1 proton. : āĻā§āĻžāϤ ā§§āĻāĻž āĻĒā§ā§°ā§āĻāύ āĻĨāĻžāĻā§āĨ¤
Q3. Hydrogen exists as: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻā§āύā§āĻā§ āĻĨāĻžāĻā§ ?
(a) H (b) Hâ (c) Hâ (d) HâO
Ans: (b) Hâ
Explanation: Hydrogen is a diatomic molecule. : āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻĻā§āĻāĻž āĻĒā§°āĻŽāĻžāĻŖā§ā§°ā§ āĻāĻ āĻŋāϤ āĻ
āĻŖā§āĨ¤
Q4. Which of the following is a property of hydrogen ? āϤāϞ⧰ āĻā§āύāĻā§ āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ⧰ āĻā§āĻŖ ?
(a) Heavy gas (b) Colored gas (c) Lightest element (d) Solid
Ans: (c) Lightest element
Explanation: Hydrogen is the lightest element. : āĻ āĻāĻāĻžāĻāϤāĻā§ āĻĒā§āĻšā§° āĻŽā§āϞāĨ¤
Q5. Hydrogen is mainly found in: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻŽā§āĻā§āϝāϤ āĻ’āϤ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧ ?
(a) Soil (b) Water (c) Rocks (d) Metals
Ans: (b) Water
Explanation: Hydrogen is part of water (HâO). : āĻĒāĻžāύā§ā§° āĻ
āĻāĻļ āĻšāĻŋāĻāĻžāĻĒā§ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤
Q6. Hydrogen is classified as: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύāĻ 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: Hydrogen is a non-metal gas. : āĻ āĻ
āϧāĻžāϤ⧠āĻā§āĻāĨ¤
Q7. How many electrons are present in hydrogen atom ? āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻĒā§°āĻŽāĻžāĻŖā§āϤ āĻāĻŋāĻŽāĻžāύ āĻāϞā§āĻā§āĻā§ā§°āύ āĻĨāĻžāĻā§ ?
(a) 2 (b) 1 (c) 0 (d) 3
Ans: (b) 1
Explanation: Hydrogen has 1 electron. : āĻā§āĻžāϤ ā§§āĻāĻž āĻāϞā§āĻā§āĻā§ā§°āύ āĻĨāĻžāĻā§āĨ¤
Q8. Hydrogen is used as: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻāĻŋāĻšā§° āĻŦāĻžāĻŦā§ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ ?
(a) Fuel (b) Plastic (c) Salt (d) Glass
Ans: (a) Fuel
Explanation: Hydrogen is used as a fuel. : āĻ āĻāύā§āϧāύ āĻšāĻŋāĻāĻžāĻĒā§ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧāĨ¤
Q9. Which element combines with hydrogen to form water ? : āĻĒāĻžāύ⧠āĻāĻ āύ āĻā§°āĻŋāĻŦāϞ⧠āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ⧠āĻā§āύāĻā§ āĻŽā§āϞ⧰ āϏā§āϤ⧠āϝā§āĻā§āϤ āĻšāϝāĻŧ ?
(a) Nitrogen (b) Oxygen (c) Carbon (d) Helium
Ans: (b) Oxygen
Explanation: Water = HâO. : āĻĒāĻžāύ⧠= HâOāĨ¤
Q10. Hydrogen is most abundant in: āĻšāĻžāĻāĻĄā§ā§°’āĻā§āύ āĻāĻāĻžāĻāϤāĻā§ āĻŦā§āĻāĻŋ 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 āĻāĻāĻžāĻāϤāĻā§ āĻŦā§āĻāĻŋ āĻĒā§ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤