Zirconium (Zr) VS Hafnium (Hf)
A definitive side-by-side comparison of two essential element profiles.
VS
Main Differences
Zirconium (Zr) is an element in the transition metals category with an atomic number of 40. Hafnium (Hf) is an element in the transition metals category with an atomic number of 72.
Hafnium (Hf) is 2.0x denser than Zirconium (Zr). However, Hafnium (Hf) melts at a higher temperature than Zirconium (Zr) (a difference of 378.0 Kelvin).
Where do the names come from?
Zr Zirconium (Zr) Naming History
The name Zirconium is derived from the Arabic, ''zargun'', meaning gold coloured.
Hf Hafnium (Hf) Naming History
The name Hafnium is derived from the Latin name for Copenhagen, ''Hafnia''
Related Comparisons
Compare
Zirconium (Zr)
Hafnium (Hf)
Category
Transition Metals
Transition Metals
Atomic Number
40
72
Symbol
Zr
Hf
Atomic Mass
91.224 u
178.486 u
Group
4
4
Period
5
6
Block
d-block
d-block
Standard State (at 20°C)
solid
solid
Density
6.52 g/cm³
13.31 g/cm³
Melting Point (°C)
1854°C
2233°C
Melting Point (°F)
3369°F
4051°F
Melting Point (K)
2128 K
2506 K
Boiling Point (°C)
4406°C
4600°C
Boiling Point (°F)
7963°F
8312°F
Boiling Point (K)
4682 K
4876 K
Year Discovered:
1789
1923
CAS Number
7440-67-7
7440-58-6
Origin of Name:
The name is derived from the Arabic, ''zargun'', meaning gold coloured.
The name is derived from the Latin name for Copenhagen, ''Hafnia''