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The main observations while… (Class 10 Science 2025, Q1)

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ScienceCBSE Class 10 · Board exam 2025, set 31/5/1 · 1 mark · MCQ

CBSE Class 10 Science 2025: question 1

Set in the CBSE Class 10 board exam of 2025, paper 31/5/1, section A, question 1, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q1 · 1 mark · MCQChemical Reactions and Equations

The main observations while performing the experiment of burning magnesium ribbon in air are:

  1. (A)(i) and (iv)
  2. (B)(ii) and (iii)
  3. (C)(i) and (ii)
  4. (D)(iii) and (iv)

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 31/5/1.

Hints

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

Hint 1

Recall the colour of the flame when magnesium burns.

Hint 2

Also recall what the product looks like: it is a white powder.

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. Magnesium ribbon burns in air with a dazzling white flame and forms a white powder, magnesium oxide: .

  2. These two observations are statements (i) and (ii), so option (C) is correct.

    1 mark

Answer: (C) (i) and (ii)

Where the marks are

  • Chooses option (C) (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Chemical Reactions and Equations, one at a time, marked against the answer key and marking points.Back to the full paper2025 board paper, set 31/5/1: 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.