Chapter 15.1-pages

 Describe a pure substance and a mixture.  Compare and contrast pure substances and mixtures.  List examples of characteristics of elements, compounds and mixtures.

1. What is an element? 2. How is an element different from an atom? 3. How is pure different from impure? 4. What is differences between an element, compound and mixture? 5. What is the difference between pure and impure substances?

 Atom  Element  Pure substance  Compound  Mixture

 What does pure mean?  What are the two examples of pure?  All matter is composed of atoms  Smallest particle of an element that still retains the properties of the element ▪ (H, Cl, O)  When we say PURE…  ANYWHERE else that you see that element, it will be EXACTLY the same ▪ Same properties ▪ Same number of electrons, protons, and neutrons  Pure substances are either an ELEMENT or a COMPOUND

 What do you notice?

 What do you already know about atoms and elements???  Write on the post-it note on your desk. List 3 things that you already know.  What do you know?

What is the composition of matter? Matter Pure Matter Substance Impure Matter Mixture only 1 set of chemical and physical properties Each substance in the mixture retains its own set of chemical and physical properties

 What does pure mean?  What are some examples of chemical and physical changes?  What is an atom? Where have we seen this before?  An element is a pure substance that cannot be broken down into a simpler substance by physical or chemical means.  All elements are PURE!  Means…a substance that is made of one type of particle  ON Periodic Table: shown as only having 1 capital letter: ▪ O for oxygen; C for carbon; Ca for calcium

 How is this different from an element?  What makes up compounds?  A compound is a pure substance in which 2 or more elements are joined in a fixed proportion  All c0mpounds are PURE!  Means…a substance that is made of same type of particles  Has 2 or more capital letters  Examples: salt, water, rust

 A compound can be made or broken down into elements through a chemical change.  This means…something new is made that has DIFFERENT properties from the original

 How is this different from an element? From a compound?  What makes up mixtures?  How are they made?  A mixture is a material made up of two or more substances (elements or compounds) that can be easily separated by physical means.  All mixtures are IMPURE!  Means…a substance that is made of same type of particles  Has 2 or more capital letters

Matter MixturePure Substance Element Compound Heterogeneous Mixture Homogeneous Mixture Can be separated physically Cannot be separated physically Can see the parts Cannot see the parts Can be separated chemically Cannot be separated Most impure Most pure

1. How is an element different from an atom? 2. What is differences between an element, compound and mixture? 3. What is the difference between pure and impure substances?