The assertion that a mixture of ideal gases forms an "ideal solution" when cooled down to liquid helium temperature (4.22K) requires clarification on several aspects. First, we need to understand the behavior of gases at extremely low temperatures, particularly as they approach liquefaction, and how this correlates to the concept of an "ideal solution."

An ideal gas, by definition, is a hypothetical gas composed of many randomly moving point particles that interact only through elastic collisions and do not exert any other forces on each other. At significantly low temperatures, particularly around 4.22 K (the boiling point of helium), many gases would condense into liquids or solids, depending on their respective boiling and freezing points.

The concept of an "ideal solution" generally applies to the solution phase and is defined as a solution that obeys Raoult's Law at all concentrations for both the solvent and the solute. Raoult's Law states that the partial vapor pressure of each component in a solution is proportional to its mole fraction in the solution. This law is strictly applicable under the assumption of no volume change on mixing and similar intermolecular forces among the components, which is often not precisely true when different substances are involved.

When ideal gases are cooled to low temperatures, such as 4.22 K, and liquefy, the behavior of the resultant liquid may not necessarily align with the principles of an ideal solution. The intermolecular forces in a liquid, particularly at such low temperatures, are significantly stronger and different in nature compared to those in a gaseous state. Moreover, the assumption of similar intermolecular forces and no volume change upon mixing is quite often violated when different gases are involved.

Therefore, it is generally FALSE to claim that cooling a mixture of ideal gases to a temperature as low as 4.22 K to form a liquid would result in an ideal solution. While the gases might mix uniformly, the resulting liquid mixture can exhibit deviations from ideal solution behavior due to changes in intermolecular forces and interactions that are not accounted for by ideal gas or ideal solution theories.