During electron capture

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

During electron capture, a nucleus of

^{22}_{11}\text{Na}

absorbs one of its own orbital electrons and transforms into

^{22}_{10}\text{Ne}

. The reaction is

e^{-}+^{22}_{11}\text{Na}\;\longrightarrow\;^{22}_{10}\text{Ne}+\;?

Which particle must appear on the right-hand side to conserve both charge and lepton number? (a) a

\gamma

photon (b) a positron

(e^{+})

(\nu_e)

(d) an electron antineutrino

(\bar{\nu}_e)