question_answer

Consider the following nuclear reactions \[_{92}^{238}M\to _{y}^{x}N+2_{2}^{4}He;_{y}^{x}N\to _{B}^{A}L+2{{\beta }^{+}}\] The number of neutrons in the element L is

A) 142      

B)                                        144                        

C) 140                        

D)        146

Correct Answer: B

Solution :

Thus,