Chemistry
Atom Calculator
Work out the protons, neutrons and electrons in an atom or ion from its atomic number, mass number and charge.
Your inputs
Change any value to update the result instantly.
Electrons
10
Protons
11
Neutrons
12
Mass number (A)
23
Species
Cation with charge +1
What this calculator does
Counts the protons, neutrons and electrons of an atom or monatomic ion from its atomic number, mass number and charge.
What your result means
The headline is the electron count. Protons equal the atomic number; neutrons are the mass number minus the atomic number; a positive charge means electrons were lost.
Formula and working
p = Z; n = A − Z; e = Z − z
- 1
Collect the inputs
Atomic number (Z) = 11; Mass number (A) = 23; Ionic charge (z) = 1
- 2
Apply the formula
p = Z; n = A − Z; e = Z − z
- 3
Result
Electrons = 10
Frequently asked questions
Symbols and assumptions
- Z
- Atomic number (protons)
- A
- Mass number (protons + neutrons)
- z
- Ionic charge
- e
- Electrons = Z − z
- • The species is a single atom or monatomic ion.
- • Mass number is at least equal to the atomic number.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • It does not identify the element symbol, isotope stability or nuclear binding energy.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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