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Mole Concept, Atomic & Nuclear Calculators

All mole concept, atomic & nuclear calculators in one place.

Molar Mass / Molecular Weight Calculator

Find the molar mass (molecular weight) of any chemical formula, with a full percent composition breakdown and step-by-step working.

Grams to Moles Calculator

Convert mass to moles, or moles back to mass, using the molar mass of any chemical formula, with particle count and step-by-step working.

Moles to Grams Calculator

Convert moles to mass, or grams back to moles, using the molar mass of any chemical formula, with a mole-to-mass scaling table, particle count, and step-by-step working.

Moles to Molecules / Atoms Converter

Convert moles to the number of molecules, formula units, or atoms using Avogadro's number, with a per-element atom breakdown and step-by-step working.

Avogadro's Number Calculator

Convert moles to the number of atoms, molecules, ions, or any other particle using Avogadro's number, work backward from a particle count to moles, or start from a mass and chemical formula — with a 'how big is this number' real-world comparison and full step-by-step working.

Percent Composition by Mass Calculator

Find the percent composition by mass of every element in any chemical formula, convert those percentages into real grams for a sample of any size, work backward to the sample size needed for a target element mass, and see full step-by-step working.

Average Atomic Mass & Isotope Abundance

Calculate an element's average atomic mass from a list of isotopes and their percent abundances, or work backward to find a missing isotope abundance from two isotope masses and a known average mass, with built-in element presets and full step-by-step working.

Electron Configuration Finder

Find the full and noble-gas-shorthand electron configuration of any element or ion — type a symbol, name, or atomic number and get an orbital box diagram, an electrons-per-shell chart, and full step-by-step working.

Quantum Numbers Calculator

Find the principal, azimuthal, magnetic, and spin quantum numbers (n, l, mₗ, mₛ) of the last electron in any element or ion, or check whether your own set of quantum numbers is a valid combination — with an orbital box diagram and full step-by-step working.

Valence Electrons Finder

Find the number of valence electrons in any element or ion — type a symbol, name, or atomic number and get a Lewis dot diagram, an octet-rule check, and full step-by-step working.

Atomic & Ionic Radius Comparison

Compare the atomic radius or ionic radius of any two elements or ions in picometers — see which is bigger, a scaled size diagram, a periodic trend chart, and full step-by-step reasoning behind the result.

Electronegativity Difference & Bond Polarity

Find the electronegativity difference (ΔEN) between any two elements, see whether the bond is nonpolar covalent, polar covalent, or ionic, get the estimated percent ionic character and dipole direction, comparison and periodic trend charts, and full step-by-step working.

Nuclear Binding Energy & Mass Defect

Find the mass defect, total nuclear binding energy, and binding energy per nucleon for any nuclide, with full step-by-step working and a labelled nucleus diagram.

Radioactive Decay & Half-Life

Calculate the remaining quantity of a radioactive substance, the elapsed time, the decay constant, or the half-life itself using N = N0.e^(-lambda.t), with full step-by-step working and a labelled decay curve.

Carbon Dating & Radiometric Age Calculator

Find the age of a sample from carbon-14 or other radiometric isotopes, the percentage of parent isotope remaining, or the original quantity, with years-before-present conversion, full step-by-step working, and a decay diagram.