The atomic mass and atomic number of lead are 208 and 82. The atomic mass and atomic number of bismuth are 209 and 83. The `"neutron"//"proton"` ratio in an atom

Options

A. Is higher in lead than in bismuth
B. Is lower in lead than in bismuth
C. Is equal in both lead and bismuth
D. None of these

Answer

D

Explanation

`._(82)Pb^(208), p = 82, n = 208 - 82 = 126`
`._(83)Bi^(209), p = 83, n = 209 - 83 = 126`
`n//p` for `Pb = (126)/(82) = 1.53`
`n//p` for `Bi = (126)/(83) = 1.51`
`:. (n)/(p)` for `Pb gt (n)/(P)` for `Bi`