Two radioactive nuclei A and B are present in equal numbers to begin with. Three days later, there are 4.04 times as many A nucl

The half-life for substance A is determined to be 17.1 days. To explain: The half-life for substance B is noted to be 1.73 days. Let’s convert the 3 days elapsed time into terms of half-lives of B: 1.37 days equates to 1 half-life of B, implying 3 days translates to multiples of half-lives of B, specifically 2.19 half-lives. Consequently, the quantity of A in regard to B is expressed as follows: A = 4.04 B. For B, we can express the quantity after n half-lives as B0 / 2ⁿ. Hence, applying these relationships after 2.19 half-lives results in adjusting A similarly as A0 / 2ⁿ. Our derived equations lead us to relate the two expressions through substitutions where after cancelling A0, we derive the final calculation: 2ⁿ = 4.04 divided by 2^(2.19), which ultimately simplifies leading to 1 half-life of A totaling 17.1 days.