Platinum (Pt)
Platinum is element 78, a transition metal in period 6, group 10 of the periodic table. At room temperature it is a solid.
Electron configuration [Xe] 4f14 5d9 6s1
Electrons per shell 2, 8, 18, 32, 17, 1
Platinum data
| Atomic number | 78 |
|---|---|
| Symbol | Pt |
| Atomic mass | 195.084 u |
| Category | Transition metal |
| Group | 10 |
| Period | 6 |
| Block | d |
| State at 25 °C | solid |
| Melting point | 2041 K (1767.9 °C) |
| Boiling point | 4098 K (3824.9 °C) |
| Density | 21.09 g/cm³ |
| Electronegativity (Pauling) | 2.28 |
| Atomic radius | 128 pm |
| 1st ionization energy | 870 kJ/mol |
| Electron affinity | -205 kJ/mol |
| Oxidation states | +2, +4, +5, +6 |
| Common ion charge | 2+, 4+ |
| Discovered | Known since antiquity |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through platinum’s configuration and its ions →
Where platinum sits
Platinum belongs to the transition metals. Its Pauling electronegativity of 2.28 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Platinum FAQ
What is the electron configuration of platinum?
Platinum (Z = 78) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d9 6s1. In noble-gas shorthand that is [Xe] 4f14 5d9 6s1. This is an exception to the simple Aufbau prediction (1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d8 6s2); a half-filled or filled subshell lowers the energy.
How many valence electrons does platinum have?
10 (1 outer s + 9 d electrons; 1 in the outermost shell).
What is the atomic mass of platinum?
The standard atomic weight of platinum is 195.084 u, so one mole weighs 195.084 g.
Is platinum a metal?
Yes. Platinum is a transition metal.
What is the charge of a platinum ion?
Platinum most commonly forms Pt2+ or Pt4+.