An isotone of `_(32)Ge^(36)` is
i. `_(32)Ge^(77)` ii. `_(33)As^(77)`
iii. `_(34)Se^(77)` iv. `_(34)Se^(78)`

Options

A. Only (i) and (ii)
B. Only i(i) and (iii)
C. Only (ii) and (iv)
D. (ii),(iii) and (iv)

Answer

C

Explanation

Isotones have same number of neutrons
`_(32)Ge^(36) n = 76 - 32 = 44`
i.`_(32)Ge^(77) n = 77 - 32 = 45`
ii.`_(31)As^(77) n = 77 - 33 = 44`
iii.`_(34)Se^(36) n = 77 - 34 = 43`
iv.`_(34)Se^(36) n = 78 - 34 = 44`
So anser is c