Why it’s important: the food we eat, materials we use, and all matter can be classified by these terms

Atoms  Matter is made up of very small particles – atoms  (Different kinds of matter contain different kinds of atoms)

Elements  Basic building blocks of matter  Contain only one type of atom  Example: Gold only contains gold atoms (symbol is Au)  Example: Diamonds only contain _______ atoms (symbol is C)  carbon

Elements continued  Unique set of properties  Classified as:  Metals  Nonmetals  Metalloids

Metals  Examples: copper (Cu), Gold (Au),  Metallic luster  Good conductors – heat & electricity  Solid at room temp. (except mercury)  Malleable (bent and pounded into various shapes)  Ductile (drawn into wires w/o breaking)  Most of the elements are metals

Nonmetals  Examples: carbon, oxygen, hydrogen, nitrogen  Dull in appearance  Poor conductors – heat & electricity  Many gases at room temp  Solids are brittle  Not malleable  More than 97% of your body is made of nonmetals

Metalloids  Characteristics of metals and nonmetals  Solid at room temp  Some shiny  Many are conductors (not as good as metals)  Found between metals and nonmetals on periodic table  Silicon- used to make electronic circuits in computers and tv

Compounds  Turn to Vocabulary in back of science notebook  Vocabulary Word  Substance  Listen to the following sentence  Elements such as a bar of gold or a sheet of aluminum, are substances.  Based on the sentence what do you think the word substance means?  Substance  I think it means:  Definition: Matter of the same composition and properties ; general term

Compounds  What do you call the colorless liquid that flows from the kitchen faucet?  Water  H2O  Compound  What do you think it means?  Definition: Substance where smallest units are atoms of more than one element bonded together  Give an example  H2O2?

Compounds: flip back to note section & write  Compounds have formulas  H2O Formula (elements & # of atoms of each element) subscript (tells you # of atoms of that element that are present) subscript (tells you # of atoms of that element that are present)  Cannot be easily separated

EXAMPLES  H2O (water): 2 Hydrogen atoms, 1 oxygen atom  CO2 (carbon dioxide):  CO (carbon monoxide):  O2 (oxygen): 2 oxygen atoms  O3 (ozone):  2 H2O: 2 molecules of H2O for a total of : H= O= quantity formula always remains the same.  No matter the quantity of the compound the formula always remains the same.

Mixtures  Examples: blood, bucket of sand and water, salad, salad dressing, chocolate chip cookie, strawberry ice cream, orange juice  Turn to Vocabulary section  Mixtures:  write what you think it means (try to use the word substance in your definition)  example  Definition: 2 or more substances (elements or compounds) come together but don’t combine to make a new substance

Mixtures flip back to note section Mixtures flip back to note section  Mixtures  Examples: add 3 or 4  2 or more substance come together (no new substance)  Proportions of substances in a mixture can be changed without changing the identity of the mixture  What does that mean?

Mixture Examples: write down  Air  Mixture of nitrogen, oxygen & other gases  Vary at different times and places  It is still air  Mix of sand & water  Add more sand and you still have a mixture of sand and water

Separating Mixtures  Mixtures can be separated  Examples of ways you can separate mixtures  Liquids  Add water to a mixture of sand and sugar  Heat  Sieves or filters

Homework:  List 3 examples of compounds (cannot be any given in class)  List 3 examples of mixtures (cannot be any given in class)  Definition & 3 examples of the following  Homogeneous mixture  Heterogeneous mixture  What type of mixture is sometimes difficult to distinguish from a compound and why?  Was your breakfast a compound, homogeneous mixture, or a heterogeneous mixture? Explain.