Question

how many neutrons does the isotope of lithium have?

Explanation:

Step1: Recall atomic number and mass - number relationship

The notation shows mass - number (top number) is 8 and atomic number (bottom number) is 3 for lithium.

Step2: Use the formula for number of neutrons

The number of neutrons $n$ is given by $n = A - Z$, where $A$ is the mass - number and $Z$ is the atomic number. Here, $A = 8$ and $Z = 3$. So $n=8 - 3$.

Step3: Calculate the result

$n = 5$.

Answer:

5