A sample of a radioactive isotope has 100 nuclei of that isotope. The graph shows how many nuclei of this isotope are left in the sample as time goes on. What is the half-life of the radioactive isotope?
- A$1\,\text{hour}$
- B$4\,\text{hours}$
- C$6\,\text{nuclei}$
- D$50\,\text{nuclei}$