A solution exhibits several characteristic properties: 

• It is a homogenous mixture in which the solute and solvent molecules cannot be differentiated even under a microscope. 
• Solute particles in a solution are extremely small – less than 1 nm in diameter – and are invisible to the naked eye.  
• The particles of a solution are invisible even under a microscope. 
• The individual components of a solution cannot be separated by the process of filtration because the minute particles of the solution can pass through filter paper. 
• The path of light is not visible in a solution because the small size of the particles do not scatter a beam of light passing through them. 
• A solution is very stable - solute particles do not sediment when left undisturbed.