Mixtures

What are mixtures?

A mixture is a combination of two or more substances that are combined physically but not chemically. They keep their original identities and properties. 

They are not pure substances, because they contain more than one type of substance. Each substance in a mixture has the same chemical makeup it had before the mixture formed. 

They do not have definite properties because they do not have a defined chemical makeup.Mixtures can be separated by physical changes. 

How can mixtures be classified?  

A heterogeneous mixture does not have a uniform composition. A homogeneous mixture is made up by substances that are evenly spread throughout. 

• As suspensions: They are mixtures in which the particles of a material are spread throughout a liquid or gas but are too large to stay mixed without being shaken. Eventually the particles will settle out. 
  
• As solutions: One substance is dissolved in another substance. Many familiar solutions are liquids. But they may also be gases or solids. 
  
• As colloids: Type of mixture that falls somewhere between suspensions and solutions. The particles are spread throughout it but they are small and do not settle out quickly. They look homogeneous but are considered heterogeneous.