Beams of charged particles are deflected by an electric field. in identical conditions the angle of deflection of a particle is proportional to its charge / mass ratio. in an experiment, protons are deflected by an angle of +15°. in another experiment under identical conditions, particle y is deflected by an angle of –5°. what could be the composition of particle y?       protons    neutrons      electrons 1)      1                2                  2 2)        3              3                  5 3 )      4                5                  1