Q86 / 160 · JIPMER 2007 · Physics

The nuclei of which one of the following pairs of nuclei are isotones ?

  • Correct answer
    A
    ${ }_{34} \mathrm{Se}^{74},{ }_{31} \mathrm{Ga}^{71}$
  • B
    ${ }_{42} \mathrm{Mo}^{92},{ }_{40} \mathrm{Zr}^{92}$
  • C
    ${ }_{38} \mathrm{Sr}^{84}, 38 \mathrm{Sr}^{86}$
  • D
    ${ }_{20} \mathrm{Ca}^{40},{ }_{16} \mathrm{~S}^{32}$

Solution

The nuclei which have same number of neutrons but different atomic number and mass number are known as isotones. In choice (a) nuclei of ${ }_{34} \mathrm{Se}^{74}$ and ${ }_{31} \mathrm{Ga}^{71}$ are isotones as $A-Z=74-34=71-31=40$

Hence, the correct answer is option: 'A'.

More Nuclear Physics Questions