This is because some atoms or molecules like getting extra electrons.

We would need a lot of extra electrons to balance this out, making it seem that this model, although interesting, is not useful.

These extra electrons can break free and travel though the material.

The electric field was adjusted so that the oil drop containing the few extra electrons did not move.

The extra electron in Cl- has more room to breathe, as it were.

The daughter nucleus is left with two extra electrons from the process.

One type has atoms with extra electrons (called the n-side).

When this metal is separated into two pieces, the extra electrons in one object can no longer get back to the other.

Under certain circumstances, an atom may capture one or more extra electrons.

The extra electron joins with its proton to produce the neutron.