What is Thulium?

Thulium, the sixty-ninth element on the periodic table, is a soft, silvery lanthanide. It's rare, subtle, and shines in lasers and X-rays.

Atomic Number: 69

Symbol: Tm

Atomic Mass: 168.93 u

Category: Lanthanide

State at Room Temperature: Solid

Discovered By: Per Teodor Cleve (1879)

⚛️ Atomic Structure of Thulium

Thulium has sixty-nine protons, one hundred neutrons (in its only stable isotope, Thulium-169), and sixty-nine electrons, with thirteen in its outer shell.

  • 🟢 Protons: 69
  • 🔴 Neutrons: 100 (Stable isotope, Thulium-169)
  • 🟡 Electrons: 69

💡 Did you know? Thulium is the rarest stable lanthanide on Earth!

🔬 Thulium Properties

Thulium is soft, ductile, and reactive. It melts at 1545°C (2813°F), has a faint bluish tint, and oxidizes in air.

🧪 How Was Thulium Discovered?

In 1879, Swedish chemist Per Teodor Cleve isolated Thulium from erbium oxide, naming it after Thule, an ancient name for Scandinavia.

⚡ Uses of Thulium

  • 🔬 Lasers: Tm:YAG lasers for surgery.
  • 🩺 Medicine: Portable X-ray sources.
  • 💡 Doping: Enhances phosphors.
  • 🔍 Research: Magnetic studies.

💡 Fun Facts About Thulium

  • 🌍 Rarest stable lanthanide.
  • 🏞️ Named for Thule.
  • 🔦 Powers small X-rays.
  • 🔵 Slightly bluish.

⚠️ Safety & Precautions

Thulium is reactive and can ignite in powder form. It's mildly toxic; handle with gloves, avoid inhalation, and store in inert conditions.

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