A typical radioactive decay problem might say, after two days, a sample of carbon-14 has decayed 75%, so what is the half-life? A graphing calculator gives the ln of the left side of the equation. To get the half life, plug k into the formula when A=1/2A0 and solve for t. The formula can also be simplified to A=A0*2^(-t/h), where h is the half-life.

To make the problem easy, assume 100 grams for the original mass.

Radiometric dating is a means of determining the "age" of a mineral specimen by determining the relative amounts present of certain radioactive elements.

By "age" we mean the elapsed time from when the mineral specimen was formed.

It has the same number of protons, otherwise it wouldn't be uranium.