# hydrogen

## Hydrogen versus Helium

(Taken from wiki on Lifting gas:http://en.wikipedia.org/wiki/Lifting_gas)
Hydrogen and helium are the most commonly used lift gases. Although helium is twice as heavy as (diatomic) hydrogen, they are both so much lighter than air that this difference is inconsequential. Both provide about 9.8 N of lift (1 newton is the force required to accelerate 1 kg at 1 m/s2) per cubic meter of gas at STP.
The lifting power in air of hydrogen and helium can be calculated using the theory of buoyancy as follows:
The density at sea-level and 0 °C for air and each of the gases is:
Thus helium is almost twice as dense as hydrogen. However, buoyancy depends upon the difference of the densities (ρgas) − (ρair) rather than upon their ratios. Thus the difference in buoyancies is about 8%, as seen from the buoyancy equation:
• Buoyant mass (or effective mass) = mass × (1 − ρair/ρgas)
• Therefore the buoyant mass for one m3 of hydrogen in air is:
• 0.090 kg * (1 − (1.292 / 0.090) ) = −1.202 kg
• And the buoyant mass for one m3 of helium in air is:
• 0.178 kg * (1 − (1.292 / 0.178) ) = −1.114 kg
The negative signs indicate that these gases tend to rise in air.
Thus hydrogen's additional buoyancy compared to helium is:
• 1.202 / 1.114 ≈ 1.080, or approximately 8.0%

## Hydrogen Safety

NOAA Hydrogen Balloon Filling Procedures
http://www.nws.noaa.gov/wsom/manual/archives/NB458111.HTML

Do not let your Hydrogen mix with a significant amount of Oxygen.

Do not touch an inflated H2 balloon with a high temperature source (this was a test to see the results)

Hydrogen will not burn/explode without Oxygen

Hydrogen MSDS