Learning Objective

Calculate subatomic particles and relative atomic mass (RAM) for isotopes, with visual nucleus representation.

Isotope Calculator

Key formulas: Mass number (A) = protons + neutrons | For neutral atom: electrons = protons
Charge = protons − electrons | Ion notation: ᵃXᶻ⁺ where A = mass number, Z = charge

Protons (Z) — Atomic number

Neutrons (N)

Electrons (optional — default neutral)

Element name (optional)

Calculated Properties

Mass number (A): 12

Electrons: 6

Charge: 0 (neutral atom)

Notation: ¹²C

Nucleus Diagram

■ Proton (+) ■ Neutron (0)

Relative Atomic Mass formula:
RAM = Σ (isotope mass × % abundance) / 100

Isotope

Mass Number

% Abundance

Isotope 1

Mass number

% abundance

Isotope 2

Mass number

% abundance

Isotope 3 (optional)

Mass number

% abundance

Quick examples:

Relative Atomic Mass (RAM)

35.5

= (35 × 75.8 + 37 × 24.2) / 100