Question

A rock sample containing an isotope with a half-life of 28 million years has an initial mass of 184 grams. how much time has elapsed after three half-lives?

Answer 1

Half Life

The half life period is the time in which only half of the given population remains. It can be represented through this equation:

`f(t)=a*(1/2)^{(t)/(h)}`

• t = time passed
• a = y-intercept
• h = half life

Solving the Question

We're given:

• h = 28 million years
• a = 184 grams (this is the initial mass, after 0 time has passed)

For most questions like this, we would have to plug these values into the equation mentioned above. However, this question asks for the time elapsed after 3 half-lives.

This can be calculated simply by multiplying the given half-life by 3:

28 million years x 3

= 84 million years

Answer

84 million years