Physics

Problem

Strontium-90 (atomic number 38) is a

\beta^{-}

emitter. Which of the following nuclear equations correctly represents its decay, including the emitted lepton? a)

^{90}_{38}\mathrm{Sr} \to {}^{90}_{37}\mathrm{Rb} + e^{-} + \bar{\nu}_{e}

^{90}_{38}\mathrm{Sr} \to {}^{90}_{39}\mathrm{Y} + e^{-} + \bar{\nu}_{e}

^{90}_{38}\mathrm{Sr} \to {}^{90}_{39}\mathrm{Y} + e^{-}

^{90}_{38}\mathrm{Sr} \to {}^{90}_{39}\mathrm{Y} + e^{-} + \nu_{e}