Radioactive Decay Calculator

Calculate radioactive decay using half-life or decay constant. Find remaining nuclei, activity, or time elapsed for any isotope.

Calculate *

Isotope *

Initial Nuclei (N₀) *

nuclei

Time Elapsed (t) *

Time Unit

Show Steps

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Radioactive Decay Result

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☢️

Decay Visualization

Exponential decay curve with activity

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📋

Calculation Breakdown

Step-by-step radioactive decay calculation

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Remaining Nuclei

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📊

Activity (A)

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⏱️

Half-Life

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t₁/₂

📐

Decay Constant

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📈

Decayed Nuclei

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N₀ - N

📊

Remaining %

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(N/N₀) × 100

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Half-Lives

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t/t₁/₂

🔬

Isotope

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Element

📖

Radioactive Decay Formulas

Key nuclear physics concepts

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Radioactive Decay Tips

Understanding nuclear decay

☢️ Scientific Disclaimer: This radioactive decay calculator uses N = N₀·e^(−λt) and A = λN. Half-life values are for reference. Results are for educational purposes.