Classification of Matter Classification of Matter Matter 1. Pure Substance a. Elementb. Compound 2. Mixtures a. Homogeneous b. Heterogeneous Combine to form Bond to form

Composition is always the same, where ever it comes from (pure gold) Composition is always the same, where ever it comes from (pure gold) Composition means what it is made of Composition means what it is made of a. Element – Simplest form of matter Simplest form of matter Made up of identical atoms Made up of identical atoms Cannot be broken down Cannot be broken down B. Classification of Matter 1. Elements

b. Compounds More than 1 kind of element joined by bonds (CO 2, NaCl) More than 1 kind of element joined by bonds (CO 2, NaCl)NaCl Can only be separated by chemical reactions Can only be separated by chemical reactions Represented with a chemical formula Represented with a chemical formula Letters indicate type of element Letters indicate type of element Subscripts tell how many Subscripts tell how many

CaCO 3 1 calcium atom 3 oxygen atoms 1 carbon atom Chemical Formulas: 5 atoms total

* Molecule more than 1 atom held by covalent bonds (all elements in a molecule are nonmetals)

2. Mixtures Combination of 2 or more pure substances Combination of 2 or more pure substances Composition of mixtures varies from source to source Composition of mixtures varies from source to source Components can be separated by physical means (magnet, filter, distillation) Components can be separated by physical means (magnet, filter, distillation) NO chemical formula NO chemical formula List of ‘ingredients’ List of ‘ingredients’

a. Homogenous mixtures Is the same thing throughout one sample Is the same thing throughout one sample Also known as solutions Also known as solutions Like tap water Like tap water

Blood is not homogeneous because it has different cells…so sometimes you need additional information

b. Heterogenous Mixture Composition varies within one sample Composition varies within one sample

Aluminum Aluminum Unlined Paper Unlined Paper Gold Gold Orange juice with pulp Orange juice with pulp Fruit on the bottom yogurt Fruit on the bottom yogurt Black coffee Black coffee Diamond Diamond Buckminsterfullerene (C 60 ) Buckminsterfullerene (C 60 ) Clean Air Clean Air Octane (C 8 H 18 ) Octane (C 8 H 18 ) Glucose Glucose Oil and water Oil and water

c. Separation – physical ways to separate mixtures (chemical reactions separate elements in a compound)

- elements cannot be broken down further and still keep their properties -Some are stable and can be found by themselves in nature. Others are so unstable, they will only be found combined with other elements. - about 100 different elements -identified by 1 or 2 letter symbols. Letters often are the first letters of the name of the element (Chlorine -> Cl) -organized in a specific way into the Periodic Table of Elements Elements Element- a pure substance consisting of a single type of atom

Metals_: properties include malleability, ductility, good conductors of heat/electricity, magnetic Nonmetals_: properties include poor conductors of heat & electricity, solids are brittle & dull _Metalloids__: have both characteristics of metals and metalloids Periodic Table of the Elements The Periodic Table organizes elements into a set of patterns, arranged by increasing atomic number, invented by Russian chemist Dimitri Mendelev (1869) ownloads.shtml

Metals: Sodium (Na), Iron (Fe), and Aluminum (Al)Sodium -Shininess, magnetic -malleability: ability of a substance to be molded/formed -conductivity: ability of a substance to transfer heat/electricity Reactivity: willingness and ability to combine with other elements -Many of the elements are so reactive that they are not found alone in nature. Wanna see how reactive?reactive -brittle, dull, not magnetic, not malleable -have poor conductivity - good insulators -many are gases, tend to be reactive Nonmetals: Hydrogen (H 2 ), Oxygen (O 2 ), Carbon (C), Chlorine (Cl) Properties of Elements