⚛️ Atom Calculator
Quickly determine the number of protons, neutrons, and electrons in an atom or ion.
Number of protons in the nucleus.
Total number of protons and neutrons.
Use negative values for anions, positive for cations.
How to Use This Calculator
Input atomic number (Z)
Enter the element's atomic number. This equals the number of protons inside the nucleus.
Specify the mass number (A)
Provide the total count of protons plus neutrons for the isotope you are analyzing.
Add the ionic charge (if any)
Use negative numbers for extra electrons (anions) and positive numbers for lost electrons (cations). Leave at 0 for neutral atoms.
Click calculate
The tool displays the proton, neutron, and electron counts along with the summary of the selected isotope or ion.
Formula
Protons = Z | Neutrons = A − Z | Electrons = Z − q
Z (Atomic number): Counts the protons in the nucleus.
A (Mass number): Sum of protons and neutrons for a specific isotope.
q (Net charge): Positive when electrons are lost, negative when electrons are gained.
Once these values are known, the atomic composition follows directly from conservation of charge and the definition of an isotope.
Full Description
The atom calculator helps students, researchers, and lab technicians analyse the composition of any isotope or ion by combining three core properties: atomic number, mass number, and net charge. These parameters reveal how many subatomic particles are present, making it easier to compare isotopes, balance nuclear equations, predict ionic charges, and prepare lab reports. By instantly displaying protons, neutrons, and electrons, the tool reinforces fundamental chemistry concepts such as atomic structure, isotopic notation, and charge balance without having to reference periodic tables repeatedly.
Use this calculator when checking homework, designing introductory chemistry demonstrations, or cross-validating instrument readouts (for example, from mass spectrometry results expressed in isotopic notation). It is equally valuable in the classroom and the laboratory because it handles ions of any charge, warns you about impossible combinations, and summarises the results in a format suitable for reports or ELNs. The clear error messages encourage correct scientific notation, while the instant feedback speeds up iterative calculations.
Typical scenarios
- Isotope comparison: Evaluate how neutron counts change between isotopes such as carbon-12 vs carbon-13.
- Ionic charge checks: Confirm electron counts for ions encountered in electrochemistry or coordination chemistry.
- Teaching aids: Demonstrate how atomic number defines an element while mass number identifies the isotope.
- Nuclear equations: Verify particle conservation when balancing alpha or beta decay reactions.
- Laboratory documentation: Capture subatomic breakdowns inside lab notebooks or digital records.
Why choose this calculator?
- ✅ Error checking: Prevents impossible inputs such as negative electron counts.
- ✅ Charge-aware: Handles anions and cations by adjusting electron totals automatically.
- ✅ Clear summaries: Provides both particle counts and isotope identifiers for quick reporting.
- ✅ Mobile ready: Accessible on phones and tablets for lab or classroom use.
- ✅ Free forever: No login, subscription, or proprietary software required.
Frequently Asked Questions
What information do I need to use this calculator?
You only need the atomic number, mass number, and the ion's net charge (if the atom is not neutral).
Can I analyze isotopes with this tool?
Yes. Changing the mass number lets you explore different isotopes of the same element while keeping the atomic number constant.
How do I enter charges such as 2− or 3+?
Use -2 for a 2− anion and 3 for a 3+ cation. The calculator adjusts the electron count accordingly.
Is the calculator accurate for large atoms?
Yes. The particle relationships are exact regardless of size, provided the input values are correct integers.