Question

An isotone of ${}_{32}^{76}Ge$ is:

• A. ${}_{32}^{77}Ge$
• B. ${}_{33}^{77}As$
• C. ${}_{34}^{77}Se$
• D. ${}_{34}^{78}Se$

Answer 1

Answer: (B), (D)

${}_{34}^{78}Se$
${}_{33}^{77}As$

Isotones are atoms of different elements with same number of neutrons.
Number of neutrons in ${}_{32}^{76}Ge=76-32=44$
${}_{33}^{77}As$, number of neutrons $=77-33=44$
${}_{34}^{78}Se$, number of neutrons $=78-34=44$