Half-life is the time taken for a substance to reduce to half its original amount. It applies to radioactive isotopes, medications, and any exponentially decaying quantity.
Half-Life Formula
Frequently Asked Questions
How is remaining amount calculated?+
Remaining = Initial × (0.5)^(time ÷ half-life). After each half-life, the quantity halves.
What are common radioactive half-lives?+
Carbon-14: 5,730 years. Uranium-238: 4.5 billion years. Iodine-131: 8 days. Technetium-99m (medical imaging): 6 hours.
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