What is Protactinium?

Protactinium, the ninety-first element on the periodic table, is a rare, radioactive actinide that's hard to find and even harder to study.

Atomic Number: 91

Symbol: Pa

Atomic Mass: [231] u (most stable isotope)

Category: Actinide

State at Room Temperature: Solid

Discovered By: Otto Hahn and Lise Meitner (1917)

⚛️ Atomic Structure of Protactinium

Protactinium has ninety-one protons, one hundred forty neutrons (in its most stable isotope, Protactinium-231), and ninety-one electrons, with two in its outer shell.

  • 🟢 Protons: 91
  • 🔴 Neutrons: 140 (Most stable isotope, Protactinium-231)
  • 🟡 Electrons: 91

💡 Did you know? Protactinium's name means "before actinium" because it decays into actinium!

🔬 Protactinium Properties

Protactinium is radioactive, silvery, and dense. It has a melting point of around 1572°C (2862°F) and emits alpha particles.

🧪 How Was Protactinium Discovered?

In 1917, German scientists Otto Hahn and Lise Meitner identified Protactinium while studying uranium decay products.

⚡ Uses of Protactinium

  • 🔬 Research: Studying actinide chemistry.
  • ⏱️ Dating: Used in geochronology to date marine sediments.

💡 Fun Facts About Protactinium

  • 🌍 Extremely rare.
  • ⏳ Half-life of 32,760 years.
  • 🏞️ Found in uranium ores.
  • 🔬 Hard to isolate.

⚠️ Safety & Precautions

Protactinium is radioactive and a radiation hazard. It requires strict handling in controlled lab settings.

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