Sulfur (S): electron configuration, atomic mass and facts
Sulfur (also spelled sulphur) (S) is element 16 of the periodic table, a reactive nonmetal in period 3, group 16. Its electron configuration is [Ne] 3s2 3p4, with electrons arranged in shells 2, 8, 6, and its standard atomic weight is 32.065 u.
💡 Burns with a blue flame. Used to make sulfuric acid, the most produced industrial chemical.
▶ Watch Sulfur’s electrons orbit in the interactive periodic tableSulfur at a glance
| Symbol | S |
|---|---|
| Atomic number | 16 |
| Atomic mass | 32.065 u |
| Category | Reactive nonmetal |
| Group | 16 |
| Period | 3 |
| Block | p-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p4 |
| Noble-gas shorthand | [Ne] 3s2 3p4 |
| Electrons per shell | 2, 8, 6 |
| Outer-shell electrons | 6 |
| Electronegativity (Pauling) | 2.58 |
| State at 20 °C | solid |
Experiments with sulfur
🔩 Iron nail in copper sulfate
A more reactive metal displaces copper: the nail turns pink and the blue fades to green.
🩸 Fe³⁺ thiocyanate test
A drop of thiocyanate turns iron(III) solutions blood red.
❌ Disappearing cross
Thiosulfate + acid turns cloudy with sulfur. Warmer means faster.
Where is Sulfur on the periodic table?
Sulfur is in period 3, group 16, in the p-block. The period number matches its 3 electron shells, and the block names the subshell its last electrons fill. In the same group, Oxygen sits directly above it and Selenium sits directly below it. Elements in one group have the same number of outer-shell electrons (6 here), which is why they react in similar ways.
How to work out the electron configuration of Sulfur
Put 16 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁴ (16). In shorthand, [Ne] stands for the 10 electrons of neon, giving [Ne] 3s² 3p⁴.
How electronegative is Sulfur?
Sulfur has a Pauling electronegativity of 2.58, ranking 9 of the 100 elements with a known value (fluorine is highest at 3.98). That is high: it pulls shared electrons strongly towards itself in a bond.
Sulfur in the virtual lab
Faradium’s chemistry workbench includes these chemicals that contain sulfur: Copper sulfate crystals, Anhydrous copper sulfate, Iron(II) sulfate crystals, Aluminium sulfate, Sulfur powder, Dilute sulfuric acid, Conc. sulfuric acid, Magnesium sulfate, Copper(II) sulfate, Iron(II) sulfate, Zinc sulfate, Sodium sulfate, Sodium sulfide, Sodium sulfite, Sodium thiosulfate, Potassium thiocyanate, Sulfur dioxide. Open the Chemistry Lab to experiment with them.
Frequently asked questions
What is the electron configuration of Sulfur?
The electron configuration of Sulfur (S) is 1s2 2s2 2p6 3s2 3p4. In noble-gas shorthand it is written [Ne] 3s2 3p4.
How many electrons does Sulfur have in each shell?
Sulfur has 16 electrons arranged in shells as 2, 8, 6. It has 6 electrons in its outer shell.
What is the atomic mass of Sulfur?
The standard atomic weight of Sulfur is 32.065 u, so one mole of Sulfur atoms has a mass of about 32.065 g.
Is Sulfur a metal?
No. Sulfur is a reactive nonmetal.
Explore nearby elements
More reactive nonmetals: Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorus, Selenium. See all elements on the periodic table.