Mass numbers of the elements A , B , C and D are 30 , 60 , 90 and 120 respectively . The specific binding energy of them are 5 Me V , 8.5 MeV , 8 Me V and 7 Me V respectively . Then , in which of the following reaction/s energy is released ?
(1) `D to 2 B ` (2) `C to B + A`
(3) `B to 2 A`

Options

A. Only in (1)
B. In (2), (3)
C. In (1), (3)
D. In (1), (2) and (3)

Answer

A

Explanation

(1) `E_(1)= 2 xx 60 xx 8.5 - 120 xx 7 = +ve`
(2) `E_(2)= (60 xx 8.5 + 30 xx 5) -90 xx 8`= -ve
(3) `E_(3)= 2 xx 30 xx 5- 60 xx 8.5`= -ve