Isotope Calculator

Isotopes are versions of the same element with different numbers of neutrons — and the Isotope Calculator breaks down their nuclear properties in detail. Enter an element symbol and mass number, then select a calculation type — Basic Isotope Properties, Radioactive Decay, or Natural Abundance — to see the neutron count, proton count, atomic mass, and binding energy. For decay analysis, add an initial activity and time elapsed to also get the remaining activity and half-life.

Enter the chemical element symbol

Total number of protons and neutrons

Bq

For radioactive decay calculations

days

Time period for decay calculation

Results

Neutron Count (N)

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Proton Count (Z)

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Atomic Mass

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Binding Energy

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Half-Life

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Remaining Activity

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Results Table

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Frequently Asked Questions

What is the difference between atomic number and mass number?

Atomic number (Z) is the number of protons in an atom's nucleus, while mass number (A) is the total number of protons and neutrons. The neutron count equals mass number minus atomic number (N = A - Z).

How do I calculate the neutron count of an isotope?

To find neutron count, subtract the atomic number (protons) from the mass number: Neutrons = Mass Number - Atomic Number. For example, Carbon-14 has 14 - 6 = 8 neutrons.

What is isotopic abundance and why does it matter?

Isotopic abundance is the percentage of each isotope found naturally. It affects the average atomic mass of elements and is crucial for applications like radiometric dating and nuclear medicine.

How does radioactive decay affect isotope calculations?

Radioactive isotopes decay over time following exponential decay law. The remaining activity after time t equals initial activity × e^(-λt), where λ is the decay constant related to half-life.

What is binding energy and how is it calculated?

Binding energy is the energy required to separate all nucleons in an atom. It's calculated from the mass defect using Einstein's E=mc² equation and indicates nuclear stability.

Which isotopes are commonly used in medical applications?

Common medical isotopes include Technetium-99m for imaging, Iodine-131 for thyroid treatment, Cobalt-60 for radiation therapy, and Carbon-14 for research dating applications.

How do I interpret half-life values?

Half-life is the time required for half of a radioactive sample to decay. Short half-lives (seconds to days) indicate rapid decay, while long half-lives (years to billions of years) indicate slow decay.