Rubidium-87 (Rb-87), which has a half-life of approximately 50 billion years, decays into strontium-87 (Sr-87). The following data table shows how the amount of Rb-87 in a certain rock changes over time. Approximately
what percentage of the original Rb-87 will remain in the rock when it is 2 billion years old? Round your
answer to the nearest thousandth of a percent.
After 0.02 half-
lives
After 0.04 half-
lives
After 0.06 half-
lives
After 0.08 half-
lives
95.926
94.606
98.623
97.265
percent of Rb-87
remaining