Dy Dysprosium

Quick answerDysprosium (Dy) is a lanthanide with atomic number 66 and an atomic mass of 162.5 (2023), in period 6. It was discovered by Paul-Émile Lecoq de Boisbaudran in 1886. It is used for electric vehicle motors and wind turbines. Its electron configuration is [Xe] 4f10 6s2.

Dysprosium keeps neodymium magnets working in hot electric motors, from cars and wind turbines to headphones.

Key facts

Symbol	Dy
Atomic number	66
Atomic mass	162.5 (IUPAC standard atomic weight, 2023)
Category	lanthanide
Group	— (f-block element, no group number)
Period	6
Block	f-block
Electron configuration	[Xe] 4f10 6s2
Discovered	Paul-Émile Lecoq de Boisbaudran, 1886
Uses	electric vehicle motors, wind turbines, lasers, nuclear reactor control, data storage

Quick quiz

Three questions from the facts on this page. No sign-up, no score is saved.

1. What is the chemical symbol of Dysprosium?

Pr Ce La Dy

2. What is the atomic number of Dysprosium?

68 65 66 67

3. Which category does Dysprosium belong to?

noble gas halogen lanthanide alkali metal

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Keep exploring

• Periodic table — all 118 elements
• Promethium (Pm) — another lanthanide, atomic number 61
• Samarium (Sm) — another lanthanide, atomic number 62
• Europium (Eu) — another lanthanide, atomic number 63
• Gadolinium (Gd) — another lanthanide, atomic number 64
• Terbium (Tb) — another lanthanide, atomic number 65
• Holmium (Ho) — another lanthanide, atomic number 67
• Erbium (Er) — another lanthanide, atomic number 68
• Thulium (Tm) — another lanthanide, atomic number 69
• Ytterbium (Yb) — another lanthanide, atomic number 70
• Lutetium (Lu) — another lanthanide, atomic number 71
• All lanthanide elements — on the periodic table

Sources & last updated

• CIAAW — Standard Atomic Weights
• PubChem Periodic Table
• Wikipedia — Timeline of chemical element discoveries

Last updated: 2026-11-12. Figures are shown with their year; where sources disagree, the value is left out rather than estimated.