Which of the following particles will have minimum frequency of revolution when projected with the same velocity perpendicular to a magnetic field ?

(4)ω=QBm,For  β−,  ω1=eBme    me=Mass  of  electronFor  H+,  ω2=eBmp    mp=Mass  of  proton.For  He+,  ω3=eB4mp  and  for Li+,   ω4=eB6mp∴   ω4<  ω3<  ω2<  ω1.