 Isotopes of beryllium

Beryllium has several isotopes, but the most significant ones are: 1. **Beryllium-7 (Be-7)**: This isotope has a mass number of 7 and is a radioactive isotope with a half-life of about 53.1 days. It is produced in the atmosphere through the interaction of cosmic rays with nitrogen and oxygen. Beryllium-7 decays by beta decay into lithium-7.