39 Y Yttrium 88.906
Transition metal d-block Period 5 Group 3

Yttrium

Y · Element 39 · Transition metal

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A "rare earth" that is not actually rare, and the reason your phone screen glows the right colours.

State at 20°C Solid
Atomic mass 88.906 u
Electron configuration[Kr] 4d¹ 5s²
38Sr All 118 40Zr

Structure

The yttrium atom

Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.

Orbital cloud

Measured values

Property sheet

Every bar shows where yttrium sits among all 118 elements for that property.

Physical

Density 4.472 g/cm³ 26%
Melting point 1799 K 74%
Boiling point 3609 K 76%
Specific heat 0.298 J/g·K
Thermal conductivity 17.2 W/m·K 44%

Atomic

Atomic radius 180 pm 66%
Covalent radius 190 pm
Van der Waals radius 219 pm

Electronic

Electronegativity 1.22 22%
Ionisation energy 600.1 kJ/mol 33%
Electron affinity 29.9 kJ/mol 25%

Occurrence

Abundance in crust 33 mg/kg 76%

Identity

SymbolY
Atomic number39
Atomic mass88.9058 u
CategoryTransition metal
Blockd
Crystal structurehexagonal close-packed
Oxidation states+3
Discovered1794
Discovered byJohan Gadolin

Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.

Same element, different neutrons

Isotopes of yttrium

All yttrium atoms have the same number of protons, 39, and differ only in their number of neutrons: those variants are its isotopes. The most common, Y-89, has 50 neutrons and makes up 100% of natural yttrium.

Isotopes of yttrium found in nature, with their share of the natural element, and well-known radioactive ones
ISOTOPE Neutrons Natural Abundance Half-life Decay Mode
Y-89 most common 50 100% Stable —
Y-90 51 — 64.05 hr β⁻

Here the classroom shortcut, rounded atomic mass (88.906) minus atomic number, gives the same answer: 50.

Decay modes

β⁻
beta-minus decay

Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.

Size, to scale

How big is a yttrium atom?

Radius 180 pm — that is 0.18 nm, so about 2.78 million of them side by side would span a millimetre.

Thermal range

Solid, liquid, gas — and when

Yttrium is liquid over a 1810 K window, from 1799 K to 3609 K.

Where it sits

Position in the table

Yttrium sits in period 5, group 3. Everything in group 3 shares the same outer-electron count, which is why they behave so similarly.

Other transition metals

21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh
All transition metals

The story

What yttrium is, and how we found it

Yttrium (Y) is element 39, a silvery transition metal in group 3, below scandium. It melts at 1,526 °C (1,799 K) and has a density of 4.472 g/cm³. Although it is not a lanthanide, it is so similar to the heavier lanthanides that it occurs with them in the same ores and is counted among the rare earth elements.

Atomic structure and isotopes

Yttrium has 39 electrons in five shells, arranged 2, 8, 18, 9, 2, with the configuration [Kr] 4d¹ 5s². It almost always forms the Y³⁺ ion, which is close in size to the ions of holmium and dysprosium; that is why it behaves like a heavy lanthanide.

Natural yttrium is a single stable isotope, yttrium-89. Radioactive yttrium-90, with a half-life of 64 hours, is used to treat liver cancer.

The discovery of yttrium

A black stone from Ytterby (1787)

In 1787 the Swedish army officer and amateur chemist Carl Axel Arrhenius found a heavy black mineral in a feldspar quarry at Ytterby, near Stockholm. It was later named gadolinite.

Gadolin's new earth (1794)

In 1794 the Finnish chemist Johan Gadolin analyzed the mineral and found a new oxide, or "earth", making up about 38% of it. In 1797 Anders Gustaf Ekeberg confirmed the finding and named it yttria.

Many elements from one earth

Yttria turned out to be a mixture. During the 19th century chemists separated terbium, erbium, ytterbium and other rare earths from it, and the village of Ytterby gave its name to four elements: yttrium, ytterbium, terbium and erbium. Friedrich Wöhler prepared impure yttrium metal in 1828.

Applications

What yttrium is used for

Phosphors and lighting

Yttrium compounds are hosts for light-emitting phosphors. Cerium-doped yttrium aluminum garnet (YAG) converts blue light into yellow in most white LEDs, and europium-doped yttrium compounds gave the red color of cathode-ray tube televisions (yttrium oxysulfide) and fluorescent lamps (yttrium oxide).

Ceramics, lasers and superconductors

  • Stabilized zirconia: yttrium oxide stabilizes zirconia for heat-resistant coatings on jet engine turbine blades, oxygen sensors, fuel cells and strong white dental crowns.
  • Lasers: neodymium-doped YAG (Nd:YAG) lasers are used in industry, medicine and research.
  • Superconductors: yttrium barium copper oxide (YBCO), first made in 1987, was the first material to superconduct above the boiling point of liquid nitrogen.

Metals and medicine

Small amounts of yttrium strengthen magnesium and aluminum alloys and improve the oxidation resistance of high-temperature alloys. In medicine, glass or resin microspheres containing yttrium-90 are injected into the arteries of the liver to irradiate tumors from inside.

In everyday life

  • LED lighting and screens: the yellow phosphor in white LEDs, including the backlights of many phone, laptop and TV screens, is yttrium aluminum garnet.
  • Dental crowns: zirconia crowns and bridges are stabilized with yttrium oxide.
  • Older televisions: the red glow of cathode-ray tube screens came from europium-doped yttrium compounds.

Where it comes from

Natural occurrence

33 mg/kg of Earth's crust · more abundant than 76% of elements

Abundance

Yttrium makes up about 33 parts per million of Earth's crust, more than lead or cobalt. Moon rocks brought back by the Apollo missions are relatively rich in yttrium.

Minerals

  • Xenotime (yttrium phosphate), the richest yttrium mineral.
  • Monazite and bastnäsite, the main rare earth ores, which contain smaller amounts.
  • Ion-adsorption clays in southern China, the most important source of yttrium and the other heavy rare earths.

Production

China produces most of the world's yttrium, and Myanmar supplies a significant share (USGS).

Handling

Safety

Health hazards

Yttrium has no known biological role. Its compounds have low to moderate toxicity, but breathing yttrium dust can irritate and damage the lungs. In the United States the OSHA limit for yttrium in workplace air is 1 mg per cubic meter.

Fire and reactivity

Solid yttrium is stable in air thanks to a thin oxide layer, but fine powder or turnings can ignite, and the metal reacts with acids, and slowly with water, to release hydrogen.

Safe handling

  • Avoid dust; use ventilation and eye and respiratory protection when handling powders.
  • Fight metal fires with a Class D extinguisher or dry sand, not water.
  • Yttrium-90 is a radioactive medical isotope, handled only under radiation safety rules.

Keep exploring

Use yttrium in the tools

Quick answers

Yttrium: common questions

What is yttrium?

Yttrium (symbol Y) is element 39 on the periodic table, a transition metal in period 5, group 3. A "rare earth" that is not actually rare, and the reason your phone screen glows the right colours. At room temperature it is a solid.

What is the electron configuration of yttrium?

Yttrium's ground-state electron configuration is [Kr] 4d¹ 5s², giving 5 occupied shells with the distribution 2, 8, 18, 9, 2.

What are the melting and boiling points of yttrium?

Yttrium melts at 1799 K (1525.9 °C) and boils at 3609 K (3335.9 °C).

What is the atomic mass of yttrium?

The standard atomic weight of yttrium is 88.906 u. That is a weighted average across its naturally occurring isotopes, which is why it is rarely a whole number.

How many neutrons does yttrium have?

The most common yttrium atom, Y-89, has 50 neutrons: its mass number, 89, minus its atomic number, 39. It makes up 100% of natural yttrium. The classroom shortcut, rounded atomic mass (88.906) minus atomic number, gives the same 50.

How dense is yttrium?

Yttrium has a density of 4.472 g/cm³. Water is 1.0 g/cm³, so a block of yttrium is about 4.5× heavier.

What is the electronegativity of yttrium?

Yttrium has a Pauling electronegativity of 1.22. The scale runs from 0.70 (francium, the least greedy for electrons) to 3.98 (fluorine, the most). Values in this middle band tend to form covalent rather than strongly ionic bonds.

Who discovered yttrium, and when?

Yttrium was discovered in 1794 by Johan Gadolin. Origin of the name: Ytterby, a Swedish village.

How common is yttrium on Earth?

Yttrium makes up about 33 mg/kg of the Earth's crust — uncommon, but not rare.

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