GROUP 18: THE NOBLE GASES

Noble Gases Overview

Also known as: Inert gases

Elements: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn), Oganesson (Og)

Common Properties: Full valence electron shells, very low chemical reactivity, colorless, odorless gases

He

Helium

Lightest
Atomic Number 2
Atomic Mass 4.00 u
Electron Config 1s²
Common Ions None
Melting Point -272°C
Density 0.18 g/L
Helium is the second most abundant element in the universe, but it's so light that it escapes Earth's atmosphere - that's why we have to extract it from natural gas!

Properties: Colorless, odorless gas, lowest boiling point, non-flammable

Applications: Balloons, cooling MRI magnets, deep-sea diving, leak detection

Drag to rotate • Scroll to zoom
Ne

Neon

Red Glow
Atomic Number 10
Atomic Mass 20.18 u
Electron Config [He] 2s² 2p⁶
Common Ions None
Melting Point -249°C
Density 0.90 g/L
Neon signs don't actually contain much neon! The characteristic red color is from neon, but other colors come from different gases like argon or mercury vapor.

Properties: Colorless, odorless gas, glows red-orange in electric discharge

Applications: Advertising signs, high-voltage indicators, lasers, cryogenics

Drag to rotate • Scroll to zoom
Ar

Argon

Most Abundant
Atomic Number 18
Atomic Mass 39.95 u
Electron Config [Ne] 3s² 3p⁶
Common Ions None
Melting Point -189°C
Density 1.78 g/L
Argon is the most abundant noble gas in Earth's atmosphere, making up almost 1% of the air we breathe - we inhale and exhale argon with every breath!

Properties: Colorless, odorless gas, most abundant noble gas in atmosphere

Applications: Welding, incandescent light bulbs, wine preservation, double-pane windows

Drag to rotate • Scroll to zoom
Kr

Krypton

White Glow
Atomic Number 36
Atomic Mass 83.80 u
Electron Config [Ar] 3d¹⁰ 4s² 4p⁶
Common Ions None
Melting Point -157°C
Density 3.75 g/L
Krypton is named after the Greek word for "hidden," and Superman's home planet was named after this element - but kryptonite is fictional!

Properties: Colorless, odorless gas, glows white in electric discharge

Applications: Photography flash lamps, high-performance lighting, lasers

Drag to rotate • Scroll to zoom
Xe

Xenon

Forms Compounds
Atomic Number 54
Atomic Mass 131.29 u
Electron Config [Kr] 4d¹⁰ 5s² 5p⁶
Common Ions Xe²⁺, Xe⁴⁺, Xe⁶⁺
Melting Point -112°C
Density 5.90 g/L
Xenon breaks the "inert" rule - it can form compounds with highly electronegative elements like fluorine and oxygen, creating xenon fluorides and oxides!

Properties: Colorless, odorless gas, forms some compounds, used in anesthesia

Applications: Anesthesia, ion propulsion for spacecraft, high-intensity lamps, medical imaging

Drag to rotate • Scroll to zoom
Rn

Radon

Radioactive
Atomic Number 86
Atomic Mass [222] u
Electron Config [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶
Common Ions None
Melting Point -71°C
Density 9.73 g/L
Radon is the leading cause of lung cancer among non-smokers! It seeps into buildings from the ground and accumulates in poorly ventilated spaces.

Properties: Colorless, odorless radioactive gas, heaviest natural noble gas

Applications: Cancer treatment, geological research, earthquake prediction

Drag to rotate • Scroll to zoom
Og

Oganesson

Synthetic
Atomic Number 118
Atomic Mass [294] u
Electron Config [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶
Common Ions Unknown
Half-life ~0.7 ms
Stability Synthetic
Oganesson is named after Yuri Oganessian, a Russian nuclear physicist - it's only the second element named after a living person (the first was seaborgium)!

Properties: Synthetic, radioactive, extremely unstable, predicted to be solid

Applications: Scientific research only

Drag to rotate • Scroll to zoom