Enter an Element Symbol and Mass Number, choose a Calculation Type, and the Isotope Calculator gives you Neutron/Proton Count, Atomic Mass, Binding Energy, and Half-Life. Add Initial Activity and Time to track decay.
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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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).
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.
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.
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.
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.
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.
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.