Please help me with both, they’re both half life problems and i would be so happy to get a response and thank you for helping me.



If the half life of radium-226 is 1,600 years, how long will it take for 93.75% of a sample of radium-226 to decay?

Sodium-24 has a half life of 15 days. What fraction of the original amount of sodium-24 will remain in a sample after 105 days?