Modern Physics
Every modern physics calculator on CalcEngines — each with its formula, a worked example, the standard it follows and the assumptions it makes.
8 calculators in this section
- Alpha, Beta and Gamma Decay: What Changes in the NucleusType the parent and the daughter and the page names the decay — and tells you the one case where Z and A cannot name it, because beta-plus decay and electron capture leave the nucleus in exactly the same place.
- Bohr Model Energy Levels and the Hydrogen Spectral Series CalculatorGive any two levels and get the line: its wavelength, its frequency, its wavenumber and whether your eye could see it — with a switch between the 13.6 eV of the textbook, the 13.605693 eV of the Rydberg constant and the 13.598287 eV that hydrogen actually has.
- de Broglie Wavelength Calculatorλ = h/p from a speed, a kinetic energy, an accelerating voltage or a momentum — with the relativistic answer printed beside the school one, because at 100 kV the formula your textbook gives is 4.8 per cent wrong and says nothing about it.
- Mass–Energy Equivalence Calculator (E = mc²)E = mc² in whichever unit the question is written in — kilograms, grams, atomic mass units or MeV/c² — built around the one conversion that actually appears in nuclear problems: 1 u is 931.49410372 MeV, and it is not a round number.
- Nuclear Binding Energy per Nucleon CalculatorMass defect to total binding energy to binding energy per nucleon, from published atomic masses to eleven figures — and the answer to the question every textbook gets slightly wrong, which is that iron-56 is not the most tightly bound nucleus.
- Photoelectric Effect: Threshold Frequency and Stopping Potential CalculatorGive the metal and the light in whichever unit your question uses — nanometres, 10¹⁴ Hz or eV — and the page returns the stopping potential, the threshold frequency and the threshold wavelength together, with hc held at its exact 2019 value of 1239.841984332 eV nm.
- Photon Energy, Wavelength and Frequency CalculatorGive a photon in any one of five units and get the other four, plus the part of the spectrum it lands in and how many of them a beam of stated power delivers each second — with hc = 1239.841984332 eV nm, which has been an exact number since 2019.
- Radioactive Dating from a Measured Activity CalculatorAn age from an activity ratio, with the half-life you choose — and the convention that matters more than the arithmetic: radiocarbon ages are still reported with Libby's wrong half-life of 5568 years, on purpose, and this page shows you what that costs.