Element 11: Sodium (Na) / āĻŽā§ŒāϞ ā§§ā§§: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ (Na) – Used in salt, glass, soaps, street lights.


Basic Information / āĻŽā§ŒāϞāĻŋāĻ• āϤāĻĨā§āϝ



  • Name: Sodium / āύāĻžāĻŽ: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ

  • Symbol: Na / āϚāĻŋāĻšā§āύ: Na

  • Atomic Number: 11 / āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž: ā§§ā§§

  • Nature: Metal / āĻĒā§ā§°āĻ•ā§ƒāϤāĻŋ: āϧāĻžāϤ⧁



Sodium is an alkali metal (Group 1). : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻāϟāĻž āĻ•ā§āώāĻžā§° āϧāĻžāϤ⧁ (āĻ—ā§‹āϟ ā§§)āĨ¤


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



  • Protons: 11 / āĻĒā§ā§°ā§‹āϟāύ: ā§§ā§§

  • Electrons: 11 / āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ: ā§§ā§§

  • Neutrons: 12 (usually) / āύāĻŋāωāĻŸā§ā§°āύ: ⧧⧍ (āϏāĻžāϧāĻžā§°āĻŖāϤ⧇)


Electronic configuration: 2, 8, 1 : āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻŦāĻŋāĻ¨ā§āϝāĻžāϏ: 2, 8, 1


Properties / āϗ⧁āĻŖāϏāĻŽā§‚āĻš



  • Soft metal / āϕ⧋āĻŽāϞ āϧāĻžāϤ⧁

  • Highly reactive / āĻŦāĻšā§āϤ āϏāĻ•ā§ā§°āĻŋāϝāĻŧ

  • Reacts with water / āĻĒāĻžāύ⧀⧰ āϏ⧈āϤ⧇ āĻŦāĻŋāĻ•ā§ā§°āĻŋāϝāĻŧāĻž āϕ⧰⧇

  • Stored in oil / āϤ⧇āϞāϤ āϏāς⧰āĻ•ā§āώāĻŖ āϕ⧰āĻž āĻšāϝāĻŧ


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



  • Common salt (NaCl) / āϏāĻžāϧāĻžā§°āĻŖ āĻ˛ā§ąāĻŖ (NaCl)

  • Sea water / āϏāĻŽā§āĻĻā§ā§°ā§° āĻĒāĻžāύ⧀āϤ


Uses / āĻŦā§āĻ¯ā§ąāĻšāĻžā§°



  • Table salt / āĻ–ā§‹ā§ąāĻžā§° āĻ˛ā§ąāĻŖ

  • Chemicals / ā§°āĻžāϏāĻžāϝāĻŧāύāĻŋāĻ• āĻĒāĻĻāĻžā§°ā§āĻĨ āϤ⧈āϝāĻŧāĻžā§°āϤ

  • Sodium vapor lamps / āφāϞ⧋ āĻŦā§āĻ¯ā§ąāĻ¸ā§āĻĨāĻžāϤ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻšāϝāĻŧ


Importance / āϗ⧁⧰⧁āĻ¤ā§āĻŦ



  • Needed for body functions / āĻĻ⧇āĻšā§° āĻŦāĻžāĻŦ⧇ āĻĒā§ā§°āϝāĻŧā§‹āϜāύ⧀āϝāĻŧ

  • Essential in food / āĻ–āĻžāĻĻā§āϝāϤ āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚āĻ°ā§āĻŖ

  • Used in industries


Why is Sodium Reactive ? / āĻ•āĻŋāϝāĻŧ āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āϏāĻ•ā§ā§°āĻŋāϝāĻŧ ?



  • It has 1 electron in outer shell. : āχāϝāĻŧāĻžā§° āĻŦāĻžāĻšā§āϝāĻŋāĻ• āĻ–ā§‹āϞāϤ ā§§āϟāĻž āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻĨāĻžāϕ⧇āĨ¤

  • So it reacts quickly. : āϏ⧇āϝāĻŧ⧇ āχ āϏāĻšāĻœā§‡ āĻŦāĻŋāĻ•ā§ā§°āĻŋāϝāĻŧāĻž āϕ⧰⧇āĨ¤


Fact / āϤāĻĨā§āϝToo much sodium in food can be harmful. : āĻ…āϧāĻŋāĻ• āĻ˛ā§ąāĻŖ āĻ–ā§‹ā§ąāĻž āĻ¸ā§āĻŦāĻžāĻ¸ā§āĻĨā§āϝ⧰ āĻŦāĻžāĻŦ⧇ āĻ•ā§āώāϤāĻŋāĻ•āĻžā§°āĻ•āĨ¤


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Sodium (Na) – 10 PYQ MCQs


Q1. Sodium belongs to which group of the periodic table ? : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻ†ā§ąā§°ā§āϤ āϏāĻžā§°āϪ⧀⧰ āϕ⧋āύāĻŸā§‹ āĻ—ā§‹āϟāϤ āĻĒ⧰⧇ ?
(a) Group 1 (b) Group 2 (c) Group 17 (d) Group 18


Ans: (a) Group 1
Explanation: Sodium is an alkali metal placed in Group 1. : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻāϟāĻž āĻ•ā§āώāĻžā§° āϧāĻžāϤ⧁, āϏ⧇āϝāĻŧ⧇ āĻ—ā§‹āϟ ā§§āϤ āĻĨāĻžāϕ⧇āĨ¤


Q2. Atomic number of sodium is: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽā§° āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž āĻ•āĻŋ ?
(a) 10 (b) 11 (c) 12 (d) 13


Ans: (b) 11
Explanation: Atomic number = number of protons = 11. : āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻž = āĻĒā§ā§°ā§‹āϟāύ⧰ āϏāĻ‚āĻ–ā§āϝāĻž = ā§§ā§§āĨ¤


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


Ans: (b) Metal
Explanation: Sodium is a metal. : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻāϟāĻž āϧāĻžāϤ⧁āĨ¤


Q4. Electronic configuration of sodium is: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽā§° āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ āĻŦāĻŋāĻ¨ā§āϝāĻžāϏ āĻ•āĻŋ ?
(a) 2, 8, 1 (b) 2, 8, 2 (c) 2, 7, 2 (d) 2, 6, 3


Ans: (a) 2, 8, 1
Explanation: Sodium has 11 electrons arranged as 2, 8, 1. : ā§§ā§§āϟāĻž āχāϞ⧇āĻ•ā§āĻŸā§ā§°āύ = 2, 8, 1āĨ¤


Q5. Sodium reacts vigorously with: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āϤ⧀āĻŦā§ā§°āĻ­āĻžā§ąā§‡ āĻ•āĻŋāĻšā§° āϏ⧈āϤ⧇ āĻŦāĻŋāĻ•ā§ā§°āĻŋāϝāĻŧāĻž āϕ⧰⧇ ?
(a) Air (b) Water (c) Soil (d) Glass


Ans: (b) Water
Explanation: Sodium reacts quickly with water. : āĻĒāĻžāύ⧀⧰ āϏ⧈āϤ⧇ āϤ⧀āĻŦā§ā§° āĻŦāĻŋāĻ•ā§ā§°āĻŋāϝāĻŧāĻž āϕ⧰⧇āĨ¤


Q6. Sodium is stored in oil because: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āϤ⧇āϞāϤ ā§°āĻžāĻ–āĻž āĻšāϝāĻŧ āĻ•āĻžā§°āĻŖ -
(a) It is heavy (b) It reacts with air and water (c) It is soft (d) It is solid


Ans: (b) It reacts with air and water
Explanation: To prevent reaction, it is kept in oil. : āĻŦāĻŋāĻ•ā§ā§°āĻŋāϝāĻŧāĻž ā§°ā§‹āϧ āϕ⧰āĻŋāĻŦāϞ⧈ āϤ⧇āϞāϤ ā§°āĻžāĻ–āĻž āĻšāϝāĻŧāĨ¤


Q7. Sodium is found in: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻ•’āϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ ?
(a) Wood (b) Salt (NaCl) (c) Plastic (d) Paper


Ans: (b) Salt (NaCl)
Explanation: Sodium is present in common salt. : āϏāĻžāϧāĻžā§°āĻŖ āĻ˛ā§ąāĻŖāϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤


Q8. Sodium is: : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻšā§ˆāϛ⧇ -
(a) Hard metal (b) Soft metal (c) Gas (d) Liquid


Ans: (b) Soft metal
Explanation: Sodium is soft and can be cut. : āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āϕ⧋āĻŽāϞ āϧāĻžāϤ⧁āĨ¤


Q9. Sodium is important for: āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻ•āĻŋāĻšā§° āĻŦāĻžāĻŦ⧇ āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚āĻ°ā§āĻŖ ?
(a) Body functions (b) Painting (c) Fuel (d) Wood


Ans: (a) Body functions
Explanation: Sodium is needed for body functions. : āĻĻ⧇āĻšā§° āĻŦāĻžāĻŦ⧇ āĻĒā§ā§°āϝāĻŧā§‹āϜāύ⧀āϝāĻŧāĨ¤


Q10. Too much sodium in food can: āĻ…āϧāĻŋāĻ• āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻ–āĻžāϞ⧇ āĻ•āĻŋ āĻšāϝāĻŧ ?
(a) Improve health (b) Harm health (c) No effect (d) Increase weight only


Ans: (b) Harm health


Explanation: Excess sodium is harmful. : āĻ…āϧāĻŋāĻ• āĻ›āĻĄāĻŋāϝāĻŧāĻžāĻŽ āĻ•ā§āώāϤāĻŋāĻ•āĻžā§°āĻ•āĨ¤