What role does the atomic number of the material play in x-ray absorption?

The atomic number of a material plays a significant role in x-ray absorption because it directly influences the absorption rate of x-rays. Higher atomic number materials possess more electrons per atom, which increases the likelihood of x-ray interactions. When x-rays pass through a material, their attenuation—how much they are absorbed or scattered—varies with the atomic number of the elements present. Materials with a higher atomic number, such as lead, effectively absorb x-rays more than materials with a lower atomic number, like aluminum. This phenomenon is central to radiographic testing, as it impacts the contrast and quality of the resulting images. Consequently, understanding the relationship between atomic number and x-ray absorption is crucial for interpreting radiographic results accurately.