The graph below shows the radioactive decay of an isotope of strontium

Based on the graph, what is the half-life of strontium?
56.2 years
14.05 years
84.3 years
28.10 years

The graph below shows the radioactive decay of an isotope of strontium Based on the graph what is the halflife of strontium 562 years 1405 years 843 years 2810 class=