Atom Calculator

Quickly relate atomic number, mass number, charge, and subatomic particles.

Core atomic properties

Atomic number (Z)

Number of protons in the nucleus.

Mass number (A)

Protons + neutrons.

Charge (z)

Net ionic charge (in units of e).

Subatomic particles

Protons (p)

Defines the element (p = Z).

Neutrons (n)

Mass number A = p + n.

Electrons (e)

Charge z = p − e.

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