The direction of the force changes, so, the ion will now rotate in the opposite direction
Explanation:
The force experienced by a moving charge in a magnetic field is (assuming the motion of the charge is perpendicular to the magnetic field)
[tex]F=qvB[/tex] (1)
where
q is the charge
v is the velocity of the particle
B is the strength of the magnetic field
Moreover, the direction of the force is perpendicular to the motion of the particle: this means that the particle moves in a circular motion under the action of this magnetic force.
Equating this force to the centripetal force,
[tex]qvB=m\frac{v^2}{r}[/tex]
Where m is the mass of the particle. So we find that the radius of the orbit (r) is
[tex]r=\frac{mv}{qB}[/tex] (2)
In this problem, an ion with initial charge +1 picks 2 electrons and its charge becomes -1.
- From eq.(1), we notice that since the sign of q changes, the direction of the force changes as well: so, the ion will now rotate in the opposite direction
- Moreover, from eq.(2) we notice that as the absolute value of q does not change, then the radius of the orbit does not change.
