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Assertion (A): Carbon shares… (Class 10 Science 2026, Q24)

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ScienceCBSE Class 10 · Board exam 2026, set 31/1/1 · 1 mark · Assertion-reason

CBSE Class 10 Science 2026: question 24

Set in the CBSE Class 10 board exam of 2026, paper 31/1/1, section B, question 24, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q24 · 1 mark · Assertion-reasonCompetency-basedCarbon and its Compounds

Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.
Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

  1. (A)Both, Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  2. (B)Both, Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  3. (C)Assertion (A) is true, but Reason (R) is false.
  4. (D)Assertion (A) is false, but Reason (R) is true.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/1/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Why can carbon not easily gain or lose 4 electrons?

Hint 2

Check whether R gives the purpose of sharing.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. Assertion: carbon has 4 valence electrons and forms covalent bonds by sharing them with carbon or other atoms. This is true.

  2. Reason: the shared pair belongs to the outer shells of both atoms, so each atom attains a noble gas configuration. This is true, and it explains why carbon shares electrons. Correct option: (A).

    1 mark

Answer: Option (A)

Where the marks are

  • Both A and R true; R correctly explains A (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Carbon and its Compounds, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 31/1/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.