how many atoms will there most likely be at the third half - life of potassium - 40 in this model? a model…

Explanation:

Step1: Recall half - life concept

The number of atoms remaining after $n$ half - lives is given by the formula $N = N_0\times(\frac{1}{2})^n$, where $N_0$ is the initial number of atoms and $n$ is the number of half - lives. Here, $N_0 = 50$ and $n = 3$.

Step2: Calculate remaining atoms

$N=50\times(\frac{1}{2})^3=50\times\frac{1}{8}=\frac{50}{8}=6.25\approx6$ (since we are talking about the number of atoms, we round to the nearest whole number).

For the age of the rock layer, if we assume each half - life is a certain time unit, and we are at the third half - life, the age of the rock layer is 3 half - life time units.

Answer:

1. There are most likely 6 atoms at the third half - life.
2. The age of the rock layer is 3 half - life time units.