Air is mainly composed of nitrogen, oxygen, and argon, which together constitute the major gases of the atmosphere. Water vapor accounts for roughly 0.25% of the atmosphere by mass.
Physical property, such as real estate, does not qualify due to the unpredictable length of the sales process. As retirement accounts, 401(k)s and IRAs operate both as liquid assets and non-liquid assets depending on the circumstance.
A liquid asset is one you can convert to cash. Thinkstock/Comstock/Getty Images. For a business, liquidity means the ability to generate cash. Nearly every asset a company has is liquid to some degree, but some are more liquid than other.