Question 1
Calculate the half-value thickness (in mm) of lead if it reduces the intensity of a beam of x-rays whose wavelength is 10 pm by a factor of two. (Assume the linear absorption coefficient of lead is 43 cm−1 for x-rays of wavelength 10 × 10−12 m.)
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0.24
◦
0.20
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0.12
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0.16
◦
0.18
Question 2
Find the number of nuclei per unit volume (n = nuclei/cm3) for lead.
atomic weight = 202.7
density = 11.5 g/cm3
Avogadro's number = 6.02 × 1023
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2.51 × 1022
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3.42 × 1022
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2.93 × 1022
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2.94 × 1023
◦
2.05 × 1021