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MHT CET · Chemistry · Chemical Kinetics

\({ }_{90} \mathrm{Th}^{228}\) emits four alpha and one beta particles. Number of neutrons in daughter element is

  1. A 129
  2. B 190
  3. C 232
  4. D 138
Verified Solution

Answer & Solution

Correct Answer

(A) 129

Step-by-step Solution

Detailed explanation

\(90 \mathrm{Th}^{228} \underset{-4 \alpha}{\longrightarrow} 82^{212} \underset{-\beta}{\longrightarrow}{ }_{83} \mathrm{Y}^{212}\)
daughter element
Number of neutrons = mass number - atomic number
\(
\begin{array}{l}
=212-83 \\
=129
\end{array}
\)