Is a solution a homogeneous or heterogeneous mixture

Solutions are always homogeneous.

Explanation:

Solution:

Solution are considered homogeneous because in solution the ratio of solute and solvent remain the same throughout the solution. Both solute and solvent are chemically combined and form a new substance.

In solution the particles of solute can not be seen through naked eye.

When the light is passed through the solution it can not scattered.

Example:

When salt is dissolve in water it makes a solution.

The solution also exist in gaseous form. For example oxygen and many other gases dissolved in nitrogen also form a solution.

Mixture:

In mixture substance are physically combined. In mixture every every individual particle retain their properties.

It can be consist of solid, liquid and gas.

Examples:

Sand in water is also a mixture.

Oil in water form mixture.