Noble Gas
🎈 🎈 🎈
He
HELIUM
From Greek "Helios" (Sun)
Atomic Number: 2
Helium is the second lightest and second most abundant element in the observable universe. It was first discovered in 1868 during a solar eclipse as an unknown yellow spectral line in the Sun's atmosphere, making it the only element discovered extraterrestrially before being found on Earth.

As a noble gas, helium is completely inert, colorless, odorless, and non-toxic. It remains liquid at temperatures close to absolute zero, making it indispensable for cooling superconducting magnets in MRI machines and particle accelerators. Its low density and non-flammability make it perfect for lifting balloons and airships.
Atomic Mass
4.0026 u
Boiling Point
-268.9°C
State at Room Temp
Gas
Abundance in Universe
~24%
🎈 Fun fact: Helium makes your voice squeaky because sound travels nearly three times faster through helium than through air! However, inhaling too much can be dangerous as it displaces oxygen. Also, Earth is actually running out of helium — it's a finite resource that escapes into space once released!