Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ — decoded step-by-step.
Solve it the standard way once — then learn the shortcut.
Q · Atoms and MoleculesMedium · 45s
Which statement correctly describes isotopes?
TopicAtoms and Molecules
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Isotopes have the same protons but different neutrons.
Final Answer: Option C — Same atomic number, different mass number