Chemistry Figures Orbital Diagram
Fe3+[Ar]4s3d

Orbital diagrams and electron configurations

Orbital Diagram draws an atom or ion’s electrons as up and down arrows in orbital boxes, with each sublevel labeled underneath, following the aufbau principle, Pauli exclusion and Hund’s rule. Pick any element and charge. Exceptions like Cr and Cu are drawn as they really are unless you switch to the filling order, and a noble gas core like [Ar] can stand in for the inner electrons.

For students to complete, the symbol, the sublevel labels or the written configuration can be blank lines, or the orbitals can be drawn empty. For a “which rule is broken?” question, click an orbital to change its electrons: the generator says whether the result is an excited state or not allowed and names the rule it breaks, and the answer key prints that with the configuration.

What you can set

  • The element (hydrogen to oganesson) and charge
  • A noble gas core, and sublevels in filling order (4s before 3d) or by shell
  • Exceptions drawn as they really are, or as the filling order predicts
  • Full or half arrows, in squares or on lines
  • The symbol, sublevel labels and configuration line shown, as blank lines, or left off, and electrons shown or orbitals empty
  • Changed orbitals, extra empty sublevels, a chart title, and an answer key line

Copying, printing and sharing

Copy the figure straight into a test, worksheet or slide, or download it as a PNG or SVG. Printing the page prints just the figure. Share link copies the page’s address with your settings in it, so anyone who opens it sees this exact figure, and presets save settings you use often in your browser. It’s free, with no sign-up.

Example figures

Frequently asked questions

How do you fill in an orbital diagram?

Fill sublevels in aufbau order (1s, 2s, 2p, 3s, 3p, 4s, 3d…). An orbital holds at most two electrons, with opposite spins (Pauli exclusion), and within a sublevel each orbital gets one electron before any gets a second (Hund’s rule).

Why are chromium and copper different?

Their real ground states don’t follow the filling order: Cr is [Ar] 4s¹ 3d⁵ and Cu is [Ar] 4s¹ 3d¹⁰. The generator draws them as they really are, or as the filling order predicts (Cr as [Ar] 4s² 3d⁴) if your class doesn’t teach exceptions.

Which electrons does a transition metal ion lose first?

Its 4s electrons, before any 3d, so Fe²⁺ is [Ar] 3d⁶ rather than [Ar] 4s² 3d⁴. Set the charge and the generator draws the ion this way.

Can I make a diagram with a mistake for students to find?

Yes. Click any orbital to make it empty, one up, one down, a pair, or two with the same spin. The generator calls the result an excited state, not allowed, or the wrong number of electrons, and names each mistake, like “Hund’s rule: 2p has a pair while one of its orbitals is empty”.

Should 4s be written before 3d?

Both are used. Choose Filling order to put 4s before 3d, in the order they fill, or By shell to put 3d with the other n = 3 sublevels.

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