Section 07

Atom and isotope calculators

Average atomic mass from isotope abundances, isotope masses in unified atomic mass units and kilograms, and hydrogen spectral lines from the Rydberg formula.

Calculators in this section: 21
Typical formula: Ā = Σ mᵢ × fᵢ

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No. 07-0275Half-Life Formula Algebra: Calculate Decay TimeAmount remaining17.6777 same as initial amountThe half-life formula in algebra is N(t) = N0(1/2)t/T, where T is the half-life. This calculator finds the rem… No. 07-0260Full Electron Configuration: How to Find ItA full electron configuration shows how an atom’s electrons are distributed among its energy levels and subshe… No. 07-0258Radioactive Decay Formula Calculator and ExamplesAmount remaining1.8946 gA radioactive decay calculator estimates how much of a radionuclide remains after a chosen time, using its ini…

Everything in Atoms & Isotopes

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Page	Works out	Example result
24Na Beta Decay Calculator Example and Explanation	24Na remaining	329,803.802 nuclei
24Na Beta Decay Calculator Formula	24Na nuclei remaining	329,804 nuclei
24Na Beta Decay Calculator: Sodium-24 to Magnesium-24	Beta-minus decay energy Q	5.515377 MeV
Atomic Mass Calculator: Isotope Abundance Method	Average atomic mass	10.8110 u
Average Atomic Mass Formula: Calculate Isotope Mass	Average atomic mass	10.8110 u
Electron Configuration: Find Any Element’s Electrons
Full Electron Configuration: How to Find It
Half-Life Formula Algebra: Calculate Decay Time	Amount remaining	17.6777 same as initial amount
Isotope Atomic Mass Calculator: Mass of One Atom From amu	Mass of one atom	1.993 × 10⁻²⁶ kg
Kinetics Half-Life Formula by Reaction Order	Half-life	693.147 s
Metal Valence Electron Configuration Calculator
Mole Calculator for a Carbon-12 Atom
Radioactive Decay Activity Formula and Calculator	Activity after elapsed time	905.72 Bq
Radioactive Decay Calculations: Formula and Examples	Quantity remaining	5.0000 g
Radioactive Decay Calculator: Calculate Remaining Activity	Remaining activity or amount	250.00 same as initial
Radioactive Decay Formula Calculator and Examples	Amount remaining	1.8946 g
Radioactive Decay Half-Life Formula and Calculator	Half-life	6,931.472 s
Radioactive Isotope Decay Calculator and Formula	Amount remaining	0.2500 g
Weighted Average Atomic Mass Calculator
Weighted Average Atomic Mass Calculator With Abundance	Average atomic mass	35.4529 u
What Does the Rydberg Equation Calculate? Hydrogen Line Wavelength Calculator	Wavelength (vacuum)	656.47 nm

Every calculator uses a standard formula and shows it, with the constants and unit factors it needs. Method and constants.