What is Selenium?

Selenium, the thirty-fourth element on the periodic table, is a non-metal with a gray or red appearance. It's essential for life and pivotal in technology.

Atomic Number: 34

Symbol: Se

Atomic Mass: 78.971 u

Category: Non-Metal

State at Room Temperature: Solid

Discovered By: J Jöns Jacob Berzelius and Johan Gottlieb Gahn (1817)

⚛️ Atomic Structure of Selenium

Selenium has thirty-four protons, forty-five neutrons (in its most common isotope, Selenium-80), and thirty-four electrons, with six in its outer shell.

  • 🟢 Protons: 34
  • 🔴 Neutrons: 45 (Most common isotope, Selenium-80)
  • 🟡 Electrons: 34

💡 Did you know? Selenium-75, a radioactive isotope, is used in medical imaging for pancreas scans!

🔬 Selenium Properties

Selenium is brittle, semiconducting, and exists in multiple forms (allotropes). It melts at 221°C (430°F) and conducts electricity better in light than in darkness.

🧪 How Was Selenium Discovered?

In 1817, Swedish chemists Jöns Jacob Berzelius and Johan Gottlieb Gahn discovered Selenium in sulfuric acid residues, naming it after the Greek word for "moon" (selene).

⚡ Uses of Selenium

  • 💻 Electronics: Photocopiers and solar cells.
  • 💊 Nutrition: Trace element in supplements and food.
  • 🏭 Industry: Glassmaking to remove color.
  • 🔬 Research: Studying its antioxidant properties.

💡 Fun Facts About Selenium

  • 🧬 Vital for human health, found in Brazil nuts.
  • 🌙 Named after the moon, contrasting with tellurium (Earth).
  • 📸 Key to early photography and xerography.
  • 🌋 Emitted from volcanoes in trace amounts.

⚠️ Safety & Precautions

Selenium is toxic in large doses, causing nausea and hair loss, but safe in trace amounts as a nutrient. Avoid inhalation of dust or fumes.

🔬 Explore More Elements