🔹 Basic Information

• Element Name: Thallium
• Discovered By: Sir William Crookes
• Year of Discovery: 1861
• Category: Post-transition Metal
• Group: 13
• State at Room Temperature: Solid (soft, bluish-gray metal) ⚙️

Thallium is a soft metal known for its shiny, bluish surface but is highly toxic.

🔸 Chemical Properties

• Chemical Symbol: Tl
• Atomic Number: 81
• Atomic Mass: ~204.38 u
• Valency: +1, +3
• Electronic Configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹

Thallium reacts easily with air and water and can be dangerous if mishandled.

📘 Basic Things to Know

Though thallium has some useful applications, it is very poisonous and must be handled carefully.

🤔 Interesting Facts

• Named after the Greek word “thallos” meaning “green shoot” because it glows bright green in flame tests 🌿
• Once used in rat poisons and insecticides, but this use is now banned in many countries due to toxicity ⚠️
• Thallium compounds can cause severe health effects — always handle with care! 🚫
• It’s used in specialized electronics and infrared detectors 🔍💻
• Some medical tests use thallium isotopes for heart scans 🫀

🔧 Common Uses

• Electronics: Components in infrared detectors and some types of semiconductors 💻
• Medical Imaging: Thallium-201 isotope helps in heart muscle scans 🫀🩺
• Optics: Used in certain types of lenses and glasses 🔍
• Research: Studied for its chemical and physical properties in labs 🔬
• Glass Manufacturing: Adds density and improves optical quality in specialty glass ⚗️

📚 Conclusion

Thallium is a rare but risky metal with important uses in technology and medicine — but it’s also highly toxic, so safety is key. For students, it’s a reminder of how elements can have both powerful benefits and dangers! ⚠️🔬