Atomic Number
78
Element 78
Platinum (Pt)
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal.
Atomic Mass
195.08 u
Category
Transition Metal
Period
6
Group
Group 10: nickel group
Phase
solid
Density
21.45 g/cm3
Electron Shells
2, 8, 18, 32, 17, 1
Atomic Structure
Protons: 78. Electrons: 78. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹ 4f¹⁴ 5d⁹
Why Platinum Matters
Platinum helps connect atomic number 78, transition metal behavior, period 6 trends, and electron shell structure. Its solid phase, atomic mass of 195.08 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹ 4f¹⁴ 5d⁹ make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Platinum was discovered 1735 by Antonio de Ulloa. Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal.
Safety and Handling Context
Platinum is presented here for learning and comparison. Pure elements and laboratory compounds can have hazards that depend on dose, form, and setting.
Related Elements
Frequently Asked Questions
- What is the atomic number of Platinum?
- Platinum has atomic number 78, which means a neutral atom has 78 protons and 78 electrons.
- What is the chemical symbol for Platinum?
- The chemical symbol for Platinum is Pt.
- What category is Platinum in?
- Platinum is classified as a transition metal and sits in period 6 of the periodic table.
Explore Platinum in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Platinum to neighboring elements without losing your place.