# In the Stern-Gerlach experiment, why is there a nonzero force even though the atoms were electrically neutral

I know that the magnetic moment of a particle is given by:

$$\vec{\mu} = \frac{gq}{2mc}\vec{S}$$

I know that in the Stern-Gerlach experiment, neutral silver atoms were used. Additionally, the deflection in this experiment was due to the force $$F = \nabla (\vec{\mu} \cdot \vec{B})$$.

How is a nonzero force experienced, given that $$\vec{\mu}$$ is dependent on charge $$q$$, which is zero for silver atoms.

You're really asking how there can be a magnetic moment $$\vec{\mu}$$ when the atom has zero charge.