Answer:
the time taken for the element to remain 1 gram is 38,400,000 unit.
Step-by-step explanation:
Given;
initial mass, m = 5 g
half life, t = 16,000,000 unit
The time taken for the element to remain 1 gram is calculated as;
mass remaining time
5 g 0
2.5 g 16,000,000
1.25 g 32,000,000
0.625 g 48,000,000
Interpolate to obtain the time at 1 gram;
1.25 g ---------------------------------- 32,000,000
1 g --------------------------------------------- x
0.625 g --------------------------------------- 48,000,000
![\frac{1.25 - 1}{1.25 - 0.625} = \frac{32,000,000 - x}{32,000,000 - 48,000,000} \\\\\frac{0.25}{0.625} = \frac{32,000,000 - x}{-16,000,000} \\\\-4,000,000= 20,000,000 - 0.625x\\\\0.625x = 20,000,000 + 4,000,000\\\\0.625x = 24,000,000\\\\x = \frac{24,000,000}{0.625} \\\\x = 38,400,000](https://tex.z-dn.net/?f=%5Cfrac%7B1.25%20-%201%7D%7B1.25%20-%200.625%7D%20%3D%20%5Cfrac%7B32%2C000%2C000%20-%20x%7D%7B32%2C000%2C000%20-%2048%2C000%2C000%7D%20%5C%5C%5C%5C%5Cfrac%7B0.25%7D%7B0.625%7D%20%3D%20%5Cfrac%7B32%2C000%2C000%20-%20x%7D%7B-16%2C000%2C000%7D%20%5C%5C%5C%5C-4%2C000%2C000%3D%2020%2C000%2C000%20-%200.625x%5C%5C%5C%5C0.625x%20%3D%2020%2C000%2C000%20%2B%204%2C000%2C000%5C%5C%5C%5C0.625x%20%3D%20%2024%2C000%2C000%5C%5C%5C%5Cx%20%3D%20%5Cfrac%7B24%2C000%2C000%7D%7B0.625%7D%20%5C%5C%5C%5Cx%20%3D%2038%2C400%2C000)
Therefore, the time taken for the element to remain 1 gram is 38,400,000 unit.