penetration

The great penetrating power of gamma rays stems from the fact that they have no electric charge and thus do not interact with matter as strongly as do charged particles. Because of their penetrating power gamma rays can be used for radiographing holes and defects in metal…

…that a 2s electron can penetrate through the core (that is, have nonzero probability of being found closer to the nucleus than the bulk of the core electron density). If penetration occurs, the electron experiences the full nuclear charge and hence has a lower energy than an electron in an…

…motion is known as the penetration. The difference between range and penetration distances results from scattering encountered by the particle along its path. For heavy charged particles with high initial velocities (those that are appreciable fractions of the speed of light), large-angle scatterings are rare. The corresponding trajectories are straight,…