Platinum (Pt) – element 78
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a transition metal in group 10, period 6 of the periodic table (d-block), and is a solid at room temperature.
Platinum (Pt) has atomic number 78, atomic mass 195.08 u and electron configuration [Xe] 4f14 5d9 6s1.
Platinum facts
| Symbol | Pt |
|---|---|
| Atomic number | 78 |
| Atomic mass | 195.08 u (g/mol) |
| Category | transition metal |
| Group | group 10 |
| Period | 6 |
| Block | d-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d9 |
| Noble-gas notation | [Xe] 4f14 5d9 6s1 |
| Electrons per shell | 2, 8, 18, 32, 17, 1 |
Bohr model and shells
Platinum has 78 electrons in 6 shells: 2, 8, 18, 32, 17, 1. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.
Physical and atomic properties
| Melting point | 2041.4 K (1768.2 °C) |
|---|---|
| Boiling point | 4098 K (3824.8 °C) |
| Density | 21.45 g/cm³ |
| Electronegativity (Pauling) | 2.28 |
| Electron affinity | 205.041 kJ/mol |
| Ionization energies | 870, 1791 kJ/mol (1st, 2nd) |
| Molar heat capacity | 25.86 J/(mol·K) |
| Discovered by | Antonio de Ulloa |
Use the atomic mass in the molar mass calculator for any formula containing Pt.
Position in the periodic table
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Frequently asked questions
What is the atomic mass of platinum?
The atomic mass of platinum is 195.08 u, so one mole of platinum atoms weighs 195.08 g.
What is the electron configuration of platinum?
Platinum has 78 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹ 4f¹⁴ 5d⁹, or [Xe] 4f¹⁴ 5d⁹ 6s¹ in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 17, 1.
Is platinum a metal?
Yes. Platinum is a transition metal.
Where is platinum on the periodic table?
Platinum is in group 10, period 6, in the d-block.
Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.