This appears to be true on the human scale, but if you "punch the wall" (accelerate hydrogen and carbon into silicon and aluminum) at say 1/10th the speed of li

This appears to be true on the human scale, but if you "punch the wall" (accelerate hydrogen and carbon into silicon and aluminum) at say 1/10th the speed of light, there will be penetration well past the surface. More obviously if you think about how easily neutrons interact compared to protons, neutrons routinely go right through people without noticing them at all because they aren't net charged so the coulomb interactions that we are familiar with in "normal" matter don't apply.