Hydrogen normal boiling point
Hydrogen normal boiling point is the temperature at which hydrogen changes from a liquid to a gas at standard atmospheric pressure.
How big is it?
20.27 K · temperature
Also -423.2 °F
Temperature · measured approximate
A little perspective
Hydrogen normal boiling point vs Boiling helium: temperature comparison
The normal boiling point of hydrogen is 16.05 K higher than the temperature of boiling helium.
Hydrogen normal boiling point is the temperature at which hydrogen changes from a liquid to a gas at standard atmospheric pressure.
Boiling helium is helium in its liquid state at its normal boiling point under standard atmospheric pressure.
Measurements, assumptions & sources +
Hydrogen normal boiling point
Temperature: 20.27 K; measured approximate.
Rounded hydrogen normal boiling point at 1 atm (101.325 kPa); this is a phase-equilibrium reference, not hydrogen's boiling temperature at every pressure.
NIST normal boiling-point reference at 1 atm, rounded to 0.01 K; purity and isotopic composition affect precision.
NIST Chemistry WebBook — Hydrogen phase change data
The marked temperature is calibrated. Unmeasured illustration details are representative.
Boiling helium
Temperature: 4.22 K; approximate.
Approximate normal boiling point of helium at one atmosphere.
NIST Chemistry WebBook — Helium phase data
The marked temperature is calibrated. Unmeasured illustration details are representative.
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Why this measurement?
Why we use 20.27 K
We compare the normal boiling point of hydrogen. This is a measured reference value rounded for comparison; check its conditions and uncertainty in the notes.
Rounded hydrogen normal boiling point at 1 atm (101.325 kPa); this is a phase-equilibrium reference, not hydrogen's boiling temperature at every pressure.
NIST normal boiling-point reference at 1 atm, rounded to 0.01 K; purity and isotopic composition affect precision.
The picture identifies the subject; the diagram compares the recorded values. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 20.27 K | Not recorded | measured approximate |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueTemperatureBoiling helium4.22 KTemperatureBoiling helium is helium in its liquid state at its normal boiling point under standard atmospheric pressure.
Around the same scaleTemperatureCosmic microwave background2.725 KTemperatureThe cosmic microwave background is faint thermal radiation filling the universe, left over from the early stages after the Big Bang.Nearest higher valueTemperatureNeon normal boiling point27.1 KTemperatureNeon normal boiling point is the temperature at which neon transitions from liquid to gas under standard atmospheric pressure.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- NIST Chemistry WebBook — Hydrogen phase change dataPhase-change reference data for hydrogen, including its normal boiling point.
There’s always another scale
Follow your curiosity.
TemperatureBoiling helium4.22 KBoiling helium is helium in its liquid state at its normal boiling point under standard atmospheric pressure.TemperatureCosmic microwave background2.725 KThe cosmic microwave background is faint thermal radiation filling the universe, left over from the early stages after the Big Bang.TemperatureAbsolute zero0 KAbsolute zero is the lowest temperature permitted by thermodynamics, where a system has the least thermal energy available to it.TemperatureUltracold atom cloud1 × 10⁻⁷ KAn ultracold atom cloud is a collection of atoms cooled to temperatures near absolute zero, used in advanced physics experiments.TemperatureBoiling nitrogen77.36 KBoiling nitrogen is nitrogen gas produced when liquid nitrogen is heated at normal atmospheric pressure.TemperatureNeon normal boiling point27.1 KNeon normal boiling point is the temperature at which neon transitions from liquid to gas under standard atmospheric pressure.TemperatureSuperfluid helium lambda point2.17 KThe superfluid helium lambda point is the temperature at which helium-4 transitions from a normal liquid to a superfluid state.TemperatureNitrogen triple point63.15 KThe nitrogen triple point is the unique temperature and pressure at which nitrogen can coexist as a solid, liquid, and gas.