7. Choose the correct answer The mass attenuation coefficient of the X-ray radiation can be expressed as follows: mu _(n)=klambda ^3Z^3 mu _(w)=klambda ^2Z^2 mu _(m)=klambda ^4Z^2

The correct answer is:<br />$\mu _{m}=k\lambda ^{4}Z^{2}$<br /><br />Explanation:<br />The mass attenuation coefficient ($\mu_m$) is a measure of the probability that a photon will be absorbed or scattered per unit distance traveled in a medium. It is typically expressed in units of cm$^{-1}$.<br /><br />The given equation for the mass attenuation coefficient is:<br />$\mu _{m}=k\lambda ^{4}Z^{2}$<br /><br />Where:<br />- $\mu_m$ is the mass attenuation coefficient<br />- $k$ is a constant<br />- $\lambda$ is the wavelength of the X-ray radiation<br />- $Z$ is the atomic number of the medium<br /><br />The other two equations provided are not correct for the mass attenuation coefficient. The first equation ($\mu_n=k\lambda ^{3}Z^{3}$) and the second equation ($\mu_w=k\lambda ^{2}Z^{2}$) do not correctly represent the mass attenuation coefficient.<br /><br />Therefore, the correct answer is the third equation: $\mu _{m}=k\lambda ^{4}Z^{2}$.