Identify the nuclide produced when thorium-234 decays by beta emission:234 90Th→ 0−1e + ? Express your answer as an isotope using prescripts.

234 90Th → 0 -1e + 234 91Pa  Explanation: Given that : Thorium 234 decays by beta emission  Beta emission = 0, - 1 e 234 90Th → 0 -1e + 234 91Pa  Hence, when Thorium 234 90 undergoes a beta Decay ; mass number remains the same at 234 while atomic number increases by 1, becoming (90 + 1) = 91 to form a protactinium nuclide.

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