The fact that a beam of particles was deflected in the presence of an electric or magnetic force led J. J. Thomson to conclude that the particles had a(n)
O A. large mass
B. electric charge
O C. negligible mass
O D. neutral charge

electric charge

Explanation:

Charged particles are deflected in an electric or a magnetic field. The particles discovered by J.J. Thomson were charged particles.

When these charged particles are passed through electric and magnetic fields, deflection occurs depending on the nature of the charge.

A positive charge is deflected towards the negative part of an electric field or the south pole of a magnetic field.

A negative charge is selected towards the positive end of an electric field or the north pole of a magnetic field.