Y Yttrium

Quick answerYttrium (Y) is a transition metal with atomic number 39 and an atomic mass of 88.906 (2023), in group 3, period 5. It was discovered by Johan Gadolin in 1794. It is used for LED phosphors and YAG lasers. Its electron configuration is [Kr] 4d1 5s2.

Yttrium makes the red phosphor in old TV screens and the crystals in lasers, and it strengthens alloys for jet engines.

Key facts

Symbol	Y
Atomic number	39
Atomic mass	88.906 (IUPAC standard atomic weight, 2023)
Category	transition metal
Group	3
Period	5
Block	d-block
Electron configuration	[Kr] 4d1 5s2
Discovered	Johan Gadolin, 1794
Uses	LED phosphors, YAG lasers, superconductors, camera lenses, cancer treatment

Quick quiz

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

1. What is the chemical symbol of Yttrium?

Y Sc Ti V

2. What is the atomic number of Yttrium?

40 41 38 39

3. Which category does Yttrium belong to?

alkali metal halogen noble gas transition metal

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Keep exploring

• Periodic table — all 118 elements
• Zinc (Zn) — another transition metal, atomic number 30
• Zirconium (Zr) — another transition metal, atomic number 40
• Niobium (Nb) — another transition metal, atomic number 41
• Molybdenum (Mo) — another transition metal, atomic number 42
• Technetium (Tc) — another transition metal, atomic number 43
• Ruthenium (Ru) — another transition metal, atomic number 44
• Rhodium (Rh) — another transition metal, atomic number 45
• Palladium (Pd) — another transition metal, atomic number 46
• Silver (Ag) — another transition metal, atomic number 47
• Cadmium (Cd) — another transition metal, atomic number 48
• All transition metal 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.