²⁹⁰₈₂X α Y e⁺ Z β⁻ P e⁻ Q In the nuclear emission stated above, the mass number and atomic…

$^{290}_{82}X \xrightarrow{\alpha} Y \xrightarrow{e^+} Z \xrightarrow{\beta^-} P \xrightarrow{e^-} Q$ In the nuclear emission stated above, the mass number and atomic number of the product $Q$ respectively, are:
A 288, 82
B 286, 81
C 280, 81
D 286, 80

Detailed Solution

$^{290}_{82}X \xrightarrow{\alpha} {}^{286}_{80}Y \xrightarrow{e^+} {}^{286}_{79}Z \xrightarrow{\beta^-} {}^{286}_{80}P \xrightarrow{e^-} {}^{286}_{81}Q$ $\alpha$-emission: A decreases by 4, Z decreases by 2 $e^+$ (positron) emission: A unchanged, Z decreases by 1 $\beta^-$ / $e^-$ emission: A unchanged, Z increases by 1 each So Q has mass number 286 and atomic number 81.

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