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  9. Q2

PPSC PCS 2015 · Question 2 of 100

Isotopes are atoms of the same element with different number of

Science & Tech

  1. AProtons
  2. BElectrons
  3. CNeutronsCorrect
  4. DPositrons

Answer: C. Neutrons

Explanation

Isotopes have the same number of protons (same element) but differ in the number of neutrons, giving different mass numbers.

Source: https://cdn.mindspritesolutions.com/examrace/SPSC/Punjab-PSC/Punjab-PSC-Past-Papers/Punjab-Civil-Service-2015-Official-Paper-1-Part-1.pdf

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