Platinum
TRANSITION METAL
Bohr Model: Electrons arranged in energy shells around the nucleus.
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver".
Quick Facts
Atomic Number 78
Period 6
Group 10
Phase Solid
Appearance silvery white
About Transition Metals
Transition metals are elements with partially filled d-orbitals. They are hard, have high melting points, and often form colored compounds.
History
Discovered By Antonio de Ulloa
Named By Unknown
Physical Properties
Atomic Mass 195.0849
Density 21.45 g/L
Molar Heat 25.86 J/(mol·K)
Phase Transition (Melting & Boiling Points)
Platinum melts at 2041.4 K and boils at 4098 K.
Atomic Properties
Electron Config [Xe] 4f14 5d9 6s1
Electronegativity 2.28
Electron Affinity 205.041 kJ/mol
Ionization Energy 870 kJ/mol
Orbital Filling Diagram
This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule.
Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down.
Electrons fill lower energy levels first and occupy orbitals singly before pairing.
Photograph
External Resources
Study Guide
Atomic Number
The number of protons in the nucleus, which defines the element.
Atomic Mass
The average mass of an atom, including protons and neutrons.
Electronegativity
A measure of how strongly an atom attracts electrons in a bond.
Ionization Energy
The energy required to remove an electron from an atom.
Electron Config
The arrangement of electrons in the atom's energy shells.