Polonium SPDF Electron Configuration Explained
Polonium has atomic number 84, meaning it has 84 electrons to arrange across its orbitals. Its ground-state electron configuration is:
Full notation: `1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁴`
Shorthand notation: `[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴`
This configuration places Polonium in the P-block of the periodic table — Period 6, Group 16. The last subshell filled (the p subshell) determines its block.
SPDF notation tells you exactly: which subshell each electron occupies, how many electrons are in it, and the energy level of each group. This is far more detail than the simpler Bohr model, which only shows shell totals.
Aufbau Filling Sequence for Polonium
The Aufbau (building-up) principle states electrons fill the lowest available energy subshell first. For Polonium (Z=84), the filling stops at the 6p⁴ subshell.
Standard Aufbau sequence:
1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d → 5p → 6s → 4f → 5d → 6p → 7s → 5f → 6d → 7p
After filling, Polonium's configuration ends at 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁴, with 6 valence electrons in its outermost subshell.
Orbital Diagram of Polonium (s, p, d, f)
The orbital diagram of Polonium expands the configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁴ into individual orbital boxes:
- Each s subshell holds max 2 electrons (1 orbital)
- Each p subshell holds max 6 electrons (3 orbitals)
- Each d subshell holds max 10 electrons (5 orbitals)
- Each f subshell holds max 14 electrons (7 orbitals)
Hund's Rule dictates that within any subshell, electrons fill each orbital singly (spin up ↑) before pairing. This avoids electron–electron repulsion. Polonium's P-block placement confirms its last orbitals are p type.
The interactive diagram above shows Polonium's complete subshell breakdown with orbital boxes for every energy level.
How to Write Polonium's Electron Configuration
Follow these steps to write Polonium's electron configuration from scratch:
Step 1: Identify the atomic number: Z = 84 — this is the total number of electrons to place.
Step 2: Follow the Aufbau sequence, filling the lowest energy subshells first:
> 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → ...
Step 3: Apply Hund's Rule inside each subshell — one electron per orbital before pairing begins.
Step 4: Apply the Pauli Exclusion Principle — each orbital holds at most 2 electrons with opposite spins.
Step 5: After filling all 84 electrons, your result should match:
> 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁴
Shorthand: Replace the preceding noble gas core with its symbol:
> [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
Why Polonium Matters (Real-World Insight)
🧠 Memory Trick
How to Remember Polonium's Structure
To remember Polonium's shell structure, think "2-8-18-32-18-6": start from the nucleus and add electrons outward shell by shell. The last number (6) is always the valence count. Po's atomic number 84 tells you the total — the shell pattern is just how those 84 electrons are arranged.
Valence Electrons & P-Block Position
Polonium has 6 valence electrons — the electrons in its highest occupied principal energy level.
As a P-block element, Polonium's valence electrons reside in p orbitals. These are the only electrons involved in chemical bonding.
| Block | Type | Max Valence e⁻ |
|---|---|---|
| s-block | Groups 1–2 | 1–2 |
| p-block | Groups 13–18 | 3–8 |
| d-block | Groups 3–12 | up to 10 |
| f-block | Lanthanides/Actinides | up to 14 |
Polonium sits in this table as a p-block element with 6 valence electrons.
→ See Polonium's valence electrons in the Bohr model for the shell-based view.
→ Electronegativity of Polonium — how strongly it attracts these electrons.
Frequently Asked Questions
Q. How many electrons does Polonium have?
Polonium has 84 electrons, matching its atomic number. In a neutral atom, these are balanced by 84 protons in the nucleus.
Q. What is the shell structure of Polonium?
The electron shell distribution for Polonium is 2, 8, 18, 32, 18, 6. This shows how all 84 electrons are arranged across 6 principal energy levels.
Q. How many valence electrons does Polonium have?
Polonium has 6 valence electrons in its outermost shell. These are responsible for its chemical bonding and placement in Group 16.
Q. What is the SPDF configuration of Polonium?
The full configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁴. This describes the exact subshell occupancy following the Aufbau principle.
Q. What block is Polonium in?
Polonium is in the P-block because its highest-energy electrons occupy p orbitals.

