Air
Density of air
1.2 kg/m³ (1–1.29)
0.00 g/cm³ · 0.1 lb/ft³
About 1.2 kg/m³ at sea level and 20 °C, so the air in a small bedroom weighs roughly 35 kg — more than most people expect, and the reason a vacuum chamber has to be built like a pressure vessel. The range here is temperature and altitude: 1.29 kg/m³ at 0 °C at sea level, 1.13 at 40 °C, and about 1.0 at 2000 m. Still air is a poor conductor at 0.026 W/(m·K), which is why every good insulator — foam, fibreglass, down, wool — works by preventing that air from moving rather than by anything the solid does.
Properties
- Density
- 1.2 kg/m³ (1–1.29) — 0.00 g/cm³
- Thermal conductivity
- 0.026 W/(m·K)
- Floats in water
- Yes
- Magnetic
- No
What it is used for
- The reference for buoyancy and for "how much does a room of air weigh"
- Insulation, when trapped in foam or fibre
- Pneumatic power and tyres
- Combustion oxidant
How it compares
Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.
air 1.2 kg/m³
Water — the float line 1,000 kg/m³
tungsten 19,250 kg/m³
gold 19,300 kg/m³
platinum 21,450 kg/m³
| Material | Density | Relative to water |
|---|---|---|
| air ← | 1.2 kg/m³ | 0.00× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |
Does it rust?
Air contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.
Is it magnetic?
Air is not a metal and has no ferromagnetic response.
Common questions
- What is the density of air?
- 1.2 kg/m³ (1–1.29), or 0.00 g/cm³.
- Does air float?
- Yes. At 1.2 kg/m³ it is less dense than water's 1,000.
- Is air magnetic?
- Air is not a metal and has no ferromagnetic response.
Related pages
- Does air float? Yes
- Ice 917 kg/m³
- Paper 800 kg/m³
- Corrugated cardboard 160 kg/m³
- Cork 200 kg/m³
- Leather 900 kg/m³
Sources
- National Oceanic and Atmospheric Administration — NOAA (Public domain (US Government))