Collision of two small particles

[kevin0960]

People say the small particle such as electron has a property that the wave has. But isn't that if particle acts like a wave, isn't it impossible to have a collision between two particles?

Because when two different waves meet together, it just go through each other without having an any effect each other.

 

[alxm]

Depends on what you mean by 'collision'. Two electrons will definitely scatter off each other, just like classical particles, albeit not with the well-defined trajectories classical particles have.

Two quantum mechanical particles can be in the same place at the same time, if they don't repel each other (e.g. the electron in an atom can be located at the nucleus). But since two electrons repel each other the probability of observing two electrons in the same spot at the same time is zero. (Depending on their quantum numbers, the Pauli principle may prohibit this as well)