🔹 Basic Information

• Element Name: Lanthanum
• Discovered By: Carl Gustaf Mosander
• Year of Discovery: 1839
• Category: Lanthanide (also sometimes grouped as a rare earth metal)
• Group: f-block (but often listed in Group 3)
• State at Room Temperature: Solid (silvery-white, soft metal) ⚙️

Lanthanum is the first element in the lanthanide series, often called the “rare earth elements,” though it’s not actually that rare!

🔸 Chemical Properties

• Chemical Symbol: La
• Atomic Number: 57
• Atomic Mass: ~138.91 u
• Valency: +3
• Electronic Configuration: [Xe] 5d¹ 6s²

Lanthanum is highly reactive, especially in moist air, where it quickly forms a white oxide coating.

📘 Basic Things to Know

Lanthanum is soft enough to be cut with a knife, similar to lead. It’s found in rare-earth minerals like monazite and bastnäsite, and often used in high-tech devices.

🤔 Interesting Facts

• The name Lanthanum comes from the Greek word “lanthanein,” meaning “to lie hidden”, because it was hard to detect in early research. 🕵️‍♂️
• It is the first and “parent” element of the lanthanides, even though it doesn’t completely fill the f-orbital.
• Lanthanum is soft, ductile, and silvery-white, but tarnishes in air.
• Though not rare, it’s hard to separate from other lanthanides due to their similar properties.
• Lanthanum can ignite if powdered and exposed to air, so it’s handled with care in labs. 🔥

🔧 Common Uses

• Camera and Telescope Lenses: Lanthanum oxide is used in optical glass for clearer images. 📷🔭
• Hybrid Car Batteries: Used in nickel-metal hydride (NiMH) rechargeable batteries (like in Toyota Prius). 🔋
• Catalysts: Helps in refining petroleum (cracking hydrocarbons). 🛢️
• Carbon Lighting: Used in movie studio lighting and projectors. 🎥💡
• Water Treatment: Lanthanum compounds are used to remove phosphates from water systems. 💧

📚 Conclusion

Lanthanum is a bright and useful metal that leads the way in the lanthanide series. Though you may not see it every day, it plays a key role in high-tech gadgets, green energy, and clean water. For students, lanthanum shows how even hidden elements can make a big impact! 🔬🌍