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Model Paper 7 — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceModel Paper 71 Mark
MCQ
Assertion (A): The atoms of different elements having same mass number but different atomic numbers are known as isobars.
Reason (R): The sum of protons and neutrons, in the isobars is always different.
  • A
    Both A and R are true and R is the correct explanation of A
  • B
    Both A and R are true but R is not the correct explanation of A.
  • ✓
    A is true but R is false.
  • D
    $A$ is false but $R$ is true.
✓

Answer

Correct option: C.
A is true but R is false.
(c) A is true but R is false.
Explanation: Sum of protons and neutrons is known as mass number which is same for isobars.

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