Yttrium
Atomic Data
| Atomic Number | 39 |
| Symbol | Y |
| Atomic Weight | 88.906 u |
| Density (STP) | 4.472 g/cm³ |
| Melting Point | 1525.85 °C (1799 K) |
| Boiling Point | 3335.85 °C (3609 K) |
| Electronegativity | 1.22 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d1 5s2 |
| Oxidation States | +3 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 5 / 3 |
| CAS Number | 7440-65-5 |
Electron Configuration
[Kr] 4d1 5s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 1 | 37 |
| O | 5 | 5s | 2 | 39 |
| Total | 39 | 39 | ||
Isotopes of Yttrium
Yttrium is monoisotopic: ⁸⁹Y is its only naturally occurring stable isotope, accounting for 100% of all natural Yttrium.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Yttrium-89 | ⁸⁹Y | 39 | 50 | 100 | Stable |
Abundance & Occurrence
Yttrium is present in Earth's crust at approximately 33 ppm by mass and at approximately 2 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Dust and fume inhalation: Yttrium metal dust and oxide are respiratory irritants; like other rare-earth metals, fine yttrium particles should not be inhaled: use respiratory protection when grinding or machining.
- Fire hazard: Yttrium metal powder is flammable; metal fires require Class D extinguishing agents: water must not be used.
- Yttrium-90: radiation: Y-90, a high-energy beta emitter (t½ = 64 h), is produced from Sr-90 decay and is used in targeted cancer therapy; medical personnel handling Y-90 must follow radiation protection protocols including shielding and dosimetry.
- General precautions: Yttrium has low acute oral toxicity; intravenous administration in animal studies causes lung, liver, and spleen granulomas: avoid systemic exposure.
Yttrium in the Real World
Real-World Uses
- White LED phosphors: Yttrium aluminium garnet doped with cerium (YAG:Ce) is the yellow-emitting phosphor coated on blue InGaN LED chips to produce the white light used in LED bulbs, backlights, and automotive headlamps.
- YAG laser crystals: Nd:YAG (yttrium aluminium garnet doped with neodymium) lasers emit at 1064 nm and are used in laser cutting, welding, ophthalmology, cosmetic skin treatments, and military rangefinders and target designators.
- High-temperature superconductors: Yttrium barium copper oxide (YBCO) is a type-II superconductor that loses electrical resistance above liquid nitrogen temperature (77 K), used in research magnets, magnetic levitation demonstrations, and prototype power cables.
- Cancer radiotherapy: Yttrium-90 is a pure beta emitter with a 64-hour half-life; Y-90 radioembolisation microspheres (SIR-Spheres, TheraSphere) treat unresectable liver cancer by delivering a concentrated radiation dose to hepatic tumours.
- Alloy strengthening: Yttrium additions to aluminium, magnesium, and zirconium alloys refine grain size and improve high-temperature oxidation resistance, used in turbine blades and high-temperature structural components.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is yttrium used for?
Yttrium's most important use is in phosphors: yttrium oxide doped with europium produces the red colour in older cathode-ray tube televisions and still in white LEDs. Yttrium aluminium garnet (YAG) crystals doped with neodymium form the gain medium of the ubiquitous Nd:YAG laser used in surgery, manufacturing, and rangefinding. Yttrium is also added to zirconia to stabilise it for use in ceramic knife blades and dental implants.
Is yttrium toxic?
Yttrium compounds are mildly toxic if ingested in significant quantities and can irritate skin and eyes. Inhalation of yttrium dust can affect the lungs. However, at the trace levels encountered in normal life, yttrium poses no significant health risk. Its chemistry is similar to other rare-earth elements.
How was yttrium discovered?
Yttrium was discovered in 1794 by Finnish chemist Johan Gadolin in a mineral from Ytterby, a quarry near Stockholm in Sweden. He isolated yttria (yttrium oxide) from the mineral gadolinite. The village of Ytterby is remarkable in the history of chemistry: it gave its name not just to yttrium, but also to erbium, terbium, and ytterbium, all discovered in minerals from the same site.
What is yttria-stabilised zirconia?
Zirconia (ZrO2) naturally undergoes a destructive phase transition on cooling that shatters it. Adding about 3–8% yttria (Y2O3) stabilises zirconia in its high-temperature tetragonal or cubic phase at room temperature. Yttria-stabilised zirconia (YSZ) is exceptionally hard and tough, used for kitchen knife blades, dental crowns, and as the solid electrolyte in oxygen sensors and solid oxide fuel cells.