Q. Which of the following make up an isotonic triad?
A) $\ _{32}^{78}Ge,_{33}^{77}As,_{31}^{74}Ga$
B) $\ _{18}^{40}Ar,_{19}^{40}K,_{20}^{40}Ca$
C) $\ _{\ \ 92}^{233}U,_{\ \ 90}^{232}Th,_{\ \ 94}^{239}Pu$
D) $\ _{\ \ 6}^{14}C{,\ }_{\ \ \ 8}^{\ 16}O{,\ }_{\ \ 7}^{15}N$
Explanation
(d)
$\ _{6}^{14}C,_{8}^{16}O,_{7}^{15}N =$isotonic triad
Isotonic=same number of neutron.
All species contain 8 neutrons.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.