beta can travel in vacuum?

I presume that you refer to [beta particles] in your question.

Beta particles are fast moving electrons. The (kinetic) energy of which derives from the dcay of a radionuclide (i.e. weak nuclear interaction). Therefore, the particles can travel with their own energy.

In fact, if beats particles is travelling in a mdeium (e.g. air or water), the molecules in the medium would absorb energy from the beta particles by collisions. This is the reason why beta particles have a range in air, and even a more shorter range in water.