Elements Compounds Mixtures have a unique set of propertieshave a unique set of properties components are protons, neutrons, and electronscomponents are protons, neutrons, and electrons have only one type of particlehave only one type of particle are pure substances cannot be separated into simpler substancescannot be separated into simpler substances some are chemically combinedsome are chemically combined combine into definite ratios to form a compoundcombine into definite ratios to form a compound found everywhere have a unique set of propertieshave a unique set of properties components are elementscomponents are elements have only one type of particlehave only one type of particle are pure substances can be separated into simpler substances by chemical means onlycan be separated into simpler substances by chemical means only combine in a definite ratio to form different compoundscombine in a definite ratio to form different compounds are chemically combinedare chemically combined found everywhere have a unique set of properties components are elements, compounds, or bothcomponents are elements, compounds, or both has two or more different types of particleshas two or more different types of particles not chemically combinednot chemically combined not pure substances can be separated by physical means into the different substances that form itcan be separated by physical means into the different substances that form it combine in any ratio

Pure Substance is a substance in which there is only one type of particle; includes elements and compounds.

Definite Ratio Combinations of Elements forming Compounds wood 1 atom of carbon, to 2 of hydrogen, to 1 of oxygen CH 2 O salt 1 atom of sodium to 1 of chlorine NaCl carbon monoxide1 atom of carbon to 1 of oxygenCO sugar carbon dioxide hydrogen peroxide water 6 atoms of carbon, to 12 of hydrogen, to 6 of oxygen 1 atom of carbon to 2 of oxygen 2 atoms of hydrogen to 2 of oxygen 2 atoms of hydrogen to one of oxygen C 6 H 12 O 6 CO 2 H2O2H2O2 H2OH2O

Element carbon silicon hydrogen A pure substance that cannot be separated into simpler substances by physical or chemical means.

ELEMENT PURE SUBSTANCE

Na

Metals Metalloids Nonmetals some are shiny some are dull some are malleable and some are not some are ductile and some are not semiconductors of electric energy have reactivity dull brittle not malleable not ductile poor conductors of thermal and electric energy some have reactivity shiny malleable ductile good conductors of thermal and electric energy have reactivity

Compound Molecule of the Compound Water ++ Chemically combined _ A pure substance composed of two or more elements that are chemically combined. hydrogen oxygen hydrogen

Mixture

+ sodium - chloride + sodium - chloride Mixture A combination of two or more substances that are not chemically combined. Sodium chloride and water molecules

COMPOUND WATER PURE SUBSTANCE

MIXTURE of TWO ELEMENTS and the COMPOUND WATER NOT A PURE SUBSTANCE

O2 oxygen Chemically combined

Properties of Compounds color shape boiling point melting point density freezing point reactivity ( combustible, explosive, and flammable) reactivity ( combustible, explosive, and flammable)

burning wood CH 2 O + O > CO 2 + H 2 O

MixtureCompound Element

ELEMENT COMPOUND WATER MIXTURE of TWO ELEMENTS and the COMPOUND WATER PURE SUBSTANCE NOT A PURE SUBSTANCE

Solution The liquid that results when water dissolves a substance.

Chemically combined ++ - H2OH2O H2OH2O Electrons being shared between atoms of hydrogen and oxygen. The Compound Water

sodium chloride NaCl Na + ion Cl - ion

+ metal sodium gas chlorine salt

H2OH2O H is the symbol of Hydrogen O is the symbol for Oxygen The subscript means each molecule of water has two atoms of hydrogen No subscript after oxygen means each molecule of water has only one atom of oxygen.

The coefficient means that there are three molecules of water. H2OH2O H2OH2O 3 3 molecule

Parts of a Chemical Equation C C + O2O2 O2O2 CO2CO2 CO2CO2 The compounds or elements on the left side of the arrow are the starting materials, or REACTANTS. The new substance produced is the PRODUCT. The product is placed to the right of the arrow. yields or produces

NaOH + HClNaCl + H 2 O A plus sign separates products when there is more than one new substance produced. A plus sign separates reactants when there is more than one.

C C + O2O2 O2O2 CO2CO2 CO2CO2 In a chemical equation the number of atoms in the reactants should always equal to the number of atoms in the products. 1 atom carbon 2 atoms oxygen 1 atom carbon 2 atoms oxygen =

Mixture CompoundElement carbon silicon oxygen hydrogen Chemically combined O2 Molecule of the Compound Water ++ Chemically combined _ + sodium - chloride Sodium chloride and water molecules A pure substance that cannot be separated into simpler substances by physical or chemical means. A pure substance composed of two or more elements that are chemically combined. A combination of two or more substances that are not chemically combined. Mixture