Half Lives for Radioactive Elements
5730 years
Nitrogen 14
Carbon 14
4.47 billion
years
Lead 206
Uranium 238
704 million
years
Lead 207
Uranium 235
14 billion
years
Lead 208
Thorium 232
48.8 billion
yrs
Strontium
87
Rubidium 87
1.25 billion
yrs
Argon 40
Potassium 40
Half life
Stable
Daughter
Radioactive
Parent