Half-Life Calculator

Calculate radioactive decay, remaining quantity, and decay constant from half-life.

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Remaining
25.0000
Decayed
75.0000
% Remaining
25.00%
Decay Constant
1.2097e-4
Half-Lives Passed
2.000

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Understanding Radioactive Decay

Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. The half-life is the time it takes for half of a radioactive sample to decay.

The Decay Formula

N(t) = N₀ × (½)^(t / t½)

Where N(t) is the remaining quantity, N₀ is the initial amount, t is elapsed time, and t½ is the half-life.

Frequently Asked Questions

Half-life is the time required for half of the radioactive atoms in a sample to decay. It is a constant for each isotope and ranges from fractions of a second to billions of years.

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