Atomic Number
72
Element 72
Hafnium (Hf)
Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals.
Atomic Mass
178.49 u
Category
Transition Metal
Period
6
Group
Group 4: titanium group
Phase
solid
Density
13.31 g/cm3
Electron Shells
2, 8, 18, 32, 10, 2
Atomic Structure
Protons: 72. Electrons: 72. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d²
Why Hafnium Matters
Hafnium helps connect atomic number 72, transition metal behavior, period 6 trends, and electron shell structure. Its solid phase, atomic mass of 178.49 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d² make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Hafnium was discovered 1923 by Dirk Coster, George de Hevesy. Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals.
Safety and Handling Context
Hafnium 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 Hafnium?
- Hafnium has atomic number 72, which means a neutral atom has 72 protons and 72 electrons.
- What is the chemical symbol for Hafnium?
- The chemical symbol for Hafnium is Hf.
- What category is Hafnium in?
- Hafnium is classified as a transition metal and sits in period 6 of the periodic table.
Explore Hafnium in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Hafnium to neighboring elements without losing your place.