Which of the following nuclear equations correctly represents beta-minus decay of thorium-234 (atomic number 90)?

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Question

Which of the following nuclear equations correctly represents beta-minus decay of thorium-234 (atomic number 90)?

Accepted Answer

²³⁴₉₀Th → ²³⁴₉₁Pa + ⁰₋₁e — Beta-minus decay increases the atomic number by 1 (90 → 91, which is protactinium) and keeps the mass number the same (234). Option B shows alpha decay, option C incorrectly decreases the atomic number, and option D shows gamma emission with no change.

Answer

²³⁴₉₀Th → ²³⁴₈₉Ac + ⁰₋₁e

Answer

²³⁴₉₀Th → ²³⁰₈₈Ra + ⁴₂He

Answer

²³⁴₉₀Th → ²³⁴₉₀Th + ⁰₀γ

Answer

²³⁴₉₀Th → ²³⁴₉₁Pa + ⁰₋₁e

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