Q. With reference to ‘Isotopes’, which of the following statements is/are correct?
1. Atoms with identical atomic numbers but different atomic mass numbers are known as isotopes.
2. Protium, Deuterium and Tritium are isotopes of carbon.
Select the correct answer from the code given below :
a) Only 2
b) Neither 1 nor 2
c) Both 1 and 2
d) Only 1
Correct Answer: d) Only 1
Question from UPPSC Prelims 2025
Explanation:
Statement 1 is correct: Isotopes are atoms of the same element (same atomic number, i.e., same number of protons) but with different mass numbers due to differing numbers of neutrons.
Statement 2 is incorrect: Protium (¹H), Deuterium (²H), and Tritium (³H) are isotopes of hydrogen, not carbon. Common isotopes of carbon are carbon-12 (¹²C), carbon-13 (¹³C), and carbon-14 (¹⁴C).
Hence, only Statement 1 is correct
