This chart ranks the elements that exist as gases by their density at standard temperature and pressure, in grams per litre. Radon, a heavy radioactive noble gas, is by far the densest elemental gas.

About: Densest Elemental Gases

Overview of the data behind this chart

This chart ranks the elements that exist as gases by their density at standard temperature and pressure, in grams per litre. Radon, a heavy radioactive noble gas, is by far the densest elemental gas.

AI Insight

Radon is the densest elemental gas at 9.73 g/L, roughly eight times denser than air and more than 100 times denser than hydrogen. As a rule, gas density tracks atomic mass: the heavy noble gases radon, xenon (5.89) and krypton (3.75) top the list, while the lightest gases, hydrogen (0.090) and helium, sit at the bottom. The reactive halogens chlorine (3.2) and fluorine (1.70) slot in among the noble gases according to their molecular weight. Everyday air, dominated by nitrogen (1.25) and oxygen (1.43), falls in the middle of this range. The more than hundredfold spread between radon and hydrogen explains why hydrogen and helium balloons float upward, while dense radon tends to collect in basements and poorly ventilated spaces.

Data source: Royal Society of Chemistry

Key Findings

Auto-computed highlights from this dataset

🏆

Radon leads with 10 in All Time.

📊

Average value in All Time: 3 · median: 2.

↔️

Gap in All Time: Radon is 108.2× larger than Hydrogen.

Chart Controls Customize your visualization

Chart Type

Bar

H-bar

Line

Area

Table

Filter by Categories

Densest Elemental Gases

Data Insights Below

Data Insights

Numbers, trends & sources behind this chart

Admin

⬡

Data Points

10 categories · 1 year

↑

Top Value

9.73

Radon

Gas Density at STP (g/L) · All Time

◈

Metrics

Gas Density at STP (g/L)

◷

Period

All Time

Single year snapshot

Category Rankings

Gas Density at STP (g/L) · All Time

#	Category	All Time
🥇	Radon	9.73
🥈	Xenon	5.89
🥉	Krypton	3.75
4	Chlorine	3.20
5	Argon	1.78
6	Fluorine	1.70
7	Oxygen	1.43
8	Nitrogen	1.25
9	Neon	0.90
10	Hydrogen	0.09

Statistical Summary — Gas Density at STP (g/L) · All Time

9.73

Maximum

0.09

Minimum

Average

Median

What This Data Shows

Auto-generated trend summaries per category

→

Radon

Recorded 9.73 Gas Density at STP (g/L) in All Time.

Source

→

Xenon

Recorded 5.89 Gas Density at STP (g/L) in All Time.

Source

→

Krypton

Recorded 3.75 Gas Density at STP (g/L) in All Time.

Source

→

Chlorine

Recorded 3.20 Gas Density at STP (g/L) in All Time.

Source

→

Argon

Recorded 1.78 Gas Density at STP (g/L) in All Time.

Source

→

Fluorine

Recorded 1.70 Gas Density at STP (g/L) in All Time.

Source

→

Oxygen

Recorded 1.43 Gas Density at STP (g/L) in All Time.

Source

→

Nitrogen

Recorded 1.25 Gas Density at STP (g/L) in All Time.

Source

→

Neon

Recorded 0.90 Gas Density at STP (g/L) in All Time.

Source

→

Hydrogen

Recorded 0.09 Gas Density at STP (g/L) in All Time.

Source

Full Data Table

10 records across 1 year

10 sourced

Category	Metric	All Time
Radon	Gas Density at STP (g/L)	9.73
Xenon	Gas Density at STP (g/L)	5.89
Krypton	Gas Density at STP (g/L)	3.75
Chlorine	Gas Density at STP (g/L)	3.20
Argon	Gas Density at STP (g/L)	1.78
Fluorine	Gas Density at STP (g/L)	1.70
Oxygen	Gas Density at STP (g/L)	1.43
Nitrogen	Gas Density at STP (g/L)	1.25
Neon	Gas Density at STP (g/L)	0.90
Hydrogen	Gas Density at STP (g/L)	0.09