The neutron to proton ratio of the daughter element after a nucleides `""_(92)U^(238)` loses an `alpha`-particle and a beta particle successively is

Options

A. 144/90
B. 143/91
C. 144/91
D. 132/91

Answer

B

Explanation

`""_(92)^(238)U rarr ""_(a)^(b)X + ""_(2)^(4)He+""_(-1)^(0)e`
`therefore 238=b+4 " "implies b=234`
`92=a+2-1 " "implies a=91`
`therefore` daughter element, `""_(91)^(234)X`
`therefore p=91, p+n =234`
`implies n=234 - 91 =143`
`therefore n//p=143//91`