Half-Life Calculator
Calculate remaining quantity after radioactive decay using the half-life formula.
Restante
12.5000
Formula
## Half-Life Formula ### Formula **N(t) = N₀ × (1/2)^(t/t½)** Where: - **N₀** = initial quantity - **t** = elapsed time - **t½** = half-life ### Properties - After 1 half-life: 50% remains - After 2 half-lives: 25% remains - After 3 half-lives: 12.5% remains - After 10 half-lives: ~0.1% remains
Exemplo Resolvido
100 units with a half-life of 5 after 15 time units.
- 01Number of half-lives = 15/5 = 3
- 02Remaining = 100 × (0.5)³
- 03= 100 × 0.125
- 04= 12.5
Perguntas Frequentes
What is half-life?
Half-life is the time required for a quantity to reduce to half of its initial value through decay. It is constant regardless of the starting amount.
Does half-life ever reach zero?
Mathematically, no. The exponential decay function asymptotically approaches zero but never reaches it. In practice, the quantity becomes negligibly small.
What are some real half-lives?
Carbon-14: 5,730 years. Uranium-238: 4.5 billion years. Iodine-131: 8 days. Caffeine in the human body: about 5 hours.
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