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Metals and Non-Metals — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceMetals and Non-Metals1 Mark
MCQ
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : On reacting with water, calcium starts floating over water.
Reason : Calcium reacts with cold water at room temperature.
  • A
    Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
  • ✓
    Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
  • C
    $A$ is true, but $R$ is false.
  • D
    $A$ is false, but $R$ is true.
✓

Answer

Correct option: B.
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Calcium floats over water because the bubbles of hydrogen gas formed get stick to the surface of the water.

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