The accelerated particles penetrate both the cell wall and membranes.

Who knows how many random particles penetrated the electrostatic field?

But gases and the finest particles can penetrate deep in the lungs and remain behind even after extensive fits of coughing.

The particle penetrated deep into the earth and seemed to be the prime constituent of cosmic rays raining on the earth from all directions.

The strength of our sun's solar wind, which is tied to solar activity, controls how many of those particles penetrate Earth's atmosphere.

Larger particles (such as actual micron-scale particles) of copper do not adequately penetrate the wood cell walls.

Because of their small size, inhaled particles may easily penetrate deep into the lungs.

This means that alpha particles from ordinary alpha decay do not penetrate skin and cause no damage to tissues below.

Relatively speaking, alpha and beta particles cannot penetrate very far into matter.

Small particles can penetrate deeply into sensitive lung tissue and damage it, causing premature death in extreme cases.