Mixtures are absolutely everywhere you look. There are an infinite number of mixtures. Anything you can combine is a mixture. In fact, most things in nature are mixtures. In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids. Look at rocks, the ocean, or even the atmosphere. They are all mixtures, and mixtures are about physical properties, not chemical properties. That statement means the individual molecules enjoy being near each other, but their fundamental chemical structure does not change when they enter the mixture. If the chemical structure changed, it would be called a reaction not a mixture.
When you see distilled water, it is a pure substance. That means that there are only water molecules in the liquid. A mixture would be a glass of water with other things dissolved inside, maybe one of those powders you like. Each of the substances in that glass keeps its own chemical properties. So, if you have some dissolved substances in water, you can boil off the water and still have those dissolved substances left over. If you have some salt in water and then boil off the water, the salt remains in the pan.
If you put sand into a glass of water, it is considered to be a mixture. You can always tell a mixture, because each of the substances can be separated from the group in different physical ways. You can always get the sand out of the water by filtering the water away. If you were busy, you could just leave the sand and water mixture alone for a few minutes. Sometimes mixtures separate on their own. When you come back, you will find that all of the sand has sunk to the bottom. Gravity was helping you with the separation. A mixture can also be made of two liquids; even something as simple as oil and water.
1. Homogenous mixturesSimply any mixture that is uniform in composition throughout. A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties. In the human body, blood plasma is an example of a homogeneous mixture. This is a colorless fluid that holds the blood cells in suspension. It makes up a little more than half of the volume of human blood. The air breathed is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth’s atmosphere has a different density, each layer of air is its own homogeneous mixture.
2. Alloy mixtures
These are some of the most important mixtures and are strong metals. These special metals are a mixture of two metals that are combined together to strengthen them. For example, brass is a mixture of zinc and copper. Stainless steel is a mixture of chromium and nickel.
3. Common mixtures
Food, such as a sweet cake when flour, sugar, butter and milk is mixed. If you mix coffee with water you get a fresh brewed beverage. Other common mixtures found in the environment are when smoke and fog are mixed, fog is the result. Ocean water is a mixture of water and salt. Even the air that is breathed is a mixture of oxygen, nitrogen, and gasses.
Mixtures and Compounds Quiz
Mixtures I: Classification Quiz
Homogeneous Mixture Examples
Heterogeneous Mixture Examples
Word Problems - Work, Rate, Mixture Quiz
2nd Grade Free Science worksheets, Games and Quizzes