Lifting gas

A lifting gas or lighter-than-air gas is a gas that has a density lower than normal atmospheric gases and rises above them as a result, making it useful in lifting lighter-than-air aircraft. Only certain lighter than air gases are suitable as lifting gases. Dry air has a density of about 1.29 g/L (gram per liter) at standard conditions for temperature and pressure (STP) and an average molecular mass of 28.97 g/mol,[1] and so lighter-than-air gases have a density lower than this.

  1. ^ "Air - Molecular Weight". www.engineeringtoolbox.com. Retrieved 2018-01-16.