Input interpretation
Ra-221 | half-life
Result
28 seconds (25.7 to 30.4 s)
Decay properties
half-life | 28 seconds (25.7 to 30.3 s) mean lifetime | 40 seconds (37.2 to 43.6 s) decay constant | 0.025 per second specific activity | 6.8×10^7 TBq/g (terabecquerels per gram) width | 1.6×10^-17 eV (electronvolts) decay modes | α (alpha emission) | ^14C (cluster emission) final decay products | Tl-205 (100%) | Pb-207 (1.2×10^-10%)
Comparison as half-life
≈ ( 0.093 ≈ 1/11 ) × half-life of uranium-241 ( ≈ 300 s )