Jlao

Radio Wave, visible light or even Gamma-ray are just some different wavelength of 'electromagnetic radiation' (right?). So for sample, lets take a 10cm (3.93inch) Concrete wall, Gamma-ray should be able to pass through it because of his small 'size' Visible-light definitively can't pass though it. But why a Radio-wave is able to pass though ? knowing that it's bigger than the visible-light. Thank you in advance for your help.