A Matter of Fact Mixtures, Elements and Compounds Adapted from: education.jlab.org/jsat/.../elements_compounds_mixtures.ppt

Mixtures, elements, compounds Scientists like to classify things. Scientists like to classify things. One way that scientists classify matter is by its composition or structure. One way that scientists classify matter is by its composition or structure. Ultimately, all matter can be classified as mixtures, elements and compounds. Ultimately, all matter can be classified as mixtures, elements and compounds.

Why isn’t it a good idea to classify matter by its phases? Because one kind of substance can exist in more than one phase – such as H 2 0. And matter changes phases rather easily. Because one kind of substance can exist in more than one phase – such as H 2 0. And matter changes phases rather easily.

Scientists ask themselves these questions? Scientists ask themselves these questions? Is the matter uniform throughout? Is the matter uniform throughout? Can it be separated by physical means? Can it be separated by physical means? Can it be separated by chemical means? Can it be separated by chemical means? By asking these questions scientists can classify matter into three categories: Mixtures, Elements, or Compounds.

Mixtures – two or more substances that are not chemically combined with each other and can be separated by physical means. Mixtures – two or more substances that are not chemically combined with each other and can be separated by physical means. The substances in a mixture retain their individual properties. The substances in a mixture retain their individual properties. Mixtures are either heterogeneous or homogeneous Mixtures are either heterogeneous or homogeneous Heterogeneous mixtures are not even throughout like salad, pizza, or Ocean water. Heterogeneous mixtures are not even throughout like salad, pizza, or Ocean water. Homogenous mixtures are even throughout like milk, blood, or Gatorade Homogenous mixtures are even throughout like milk, blood, or Gatorade All homogenous mixtures are solutions because a substance (a solute) dissolves in another (a solvent) creating the homogenous solution. All homogenous mixtures are solutions because a substance (a solute) dissolves in another (a solvent) creating the homogenous solution.

Elements – simplest form of pure substance. They are made of only one type of atom and they cannot be broken into anything else by physical or chemical means. Elements – simplest form of pure substance. They are made of only one type of atom and they cannot be broken into anything else by physical or chemical means. If it is on the Periodic Table then it is an element. If it is on the Periodic Table then it is an element.

Compounds – pure substances that are made of two or more elements that have combined during a chemical reaction. Compounds – pure substances that are made of two or more elements that have combined during a chemical reaction. Compounds can be broken into simpler substances only by chemical means. Compounds can be broken into simpler substances only by chemical means. Examples of compounds are water, hydrogen peroxide, and salt Examples of compounds are water, hydrogen peroxide, and salt

You can determine what a substance is by asking questions and using a flow chart method.

Pure Substance Element Compound Homogonous Heterogeneous Mixture