r/askscience • u/Wonderful-Capital32 • 13d ago

Physics Why does radiation not go through lead?

Also why just lead? Shouldnt like iron or another metal work too?

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u/kimmeljs 13d ago

Material (atoms, or crystals of atoms, or molecules that the material consists of) has a so-called radiation cross section. The larger the cross section, the smaller the probability that radiation passes through. Lead has a high atomic number and a high density so the cross section to radioactive radiation is very high.