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66 Dy

Chemical element · Atomic number 66

Dysprosium (Dy)

Lanthanides · Period 6 · Solid

Explore dysprosium isotopes Locate in periodic table

Element identity

Atomic number (Z)
66
Symbol
Dy
Atomic weight / isotope mass number
162.500(1)
Category
Lanthanides
Physical state (reference)
Solid
Period
6
Group (reference)
3
Block
f

Physical properties

Appearance
Silvery white
Density
8.540 g·cm⁻³
Melting point
1680 K / 1407 °C / 2565 °F
Boiling point
2840 K / 2562 °C / 4653 °F
Sublimation point
Not available

Atomic and material properties

Electron configuration
[Xe] 4f¹⁰ 6s²
Electrons per shell
K2 L8 M18 N28 O8 P2
Oxidation states
4, 3, 2, 1
Electronegativity (Pauling)
1.22
Atomic radius
228 pm
Covalent radius
192±7 pm
Molar ionization energies
1st: 573.0 kJ·mol⁻¹ 2nd: 1130 kJ·mol⁻¹ 3rd: 2200 kJ·mol⁻¹ 4th: 3990 kJ·mol⁻¹
Thermal conductivity
10.7 W·m⁻¹·K⁻¹
Molar heat capacity
27.7 J·mol⁻¹·K⁻¹
Crystal structure
Hexagonal close packed
CAS number
7429-91-6

Sources and interpretation

Snapshot exported 24 October 2026 from the element assets used by Nuclides. Properties are a reference compilation, not a new evaluation. Missing values are shown as “Not available”. Density and phase depend on temperature, pressure and allotrope; retained conditions are part of the quoted property.

Atomic weight is dimensionless. Parentheses give uncertainty in the last quoted digits. A single integer in square brackets is an isotope mass number, not a standard atomic weight. The snapshot can differ from current evaluations; consult CIAAW standard atomic weights and the IUPAC periodic table for current values and conventions.

Element properties in the App snapshot are adapted from Wikipedia. Each element page links to its source article; text adaptations are available under CC BY-SA 4.0. No third-party images are included.

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