Question

A rock outcrop was found to have 78.88% of its parent u-238 isotope remaining. approximate the age of the outcrop. the half-life of u-238 is 4.5 billion years old.

Answer 1

Answer:1.5*10^9 years

Explanation:

The half life of the substance is given i.e 4.5B years. You can change it into seconds by multiplying it with 365 and 86400.

The current no of particles is given 78.88% which will be equal to 78.88 if you assume the substance had 100 no of particle initially.

Determine the decay constant by dividing 0.69 by half life

use these values in the equation for the answer.

[ln and e are inverse functions to eachother]