MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions

Elements only one kind of atom; atoms are bonded it the element is diatomic or polyatomic Compounds two or more kinds of atoms that are bonded substance with definite makeup and properties Mixtures two or more substances that are physically mixed two or more kinds of and Both elements and compounds have a definite makeup and definite properties.

Matter Flowchart Examples: –graphite –pepper –sugar (sucrose) –paint –soda element hetero. mixture compound solution homo. mixture hetero. mixture

Pure Substances Element –composed of identical atoms –EX: copper wire, aluminum foil

Pure Substances Compound –composed of 2 or more elements in a fixed ratio –properties differ from those of individual elements –EX: table salt (NaCl)

Pure Substances Law of Definite Composition –A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions –Elements can combine in different ratios to form different compounds.

Pure Substances For example… Two different compounds, each has a definite composition. Carbon, C Oxygen, O Carbon monoxide, CO Carbon, C Oxygen, O Oxygen, O Carbon dioxide, CO 2

Mixtures Variable combination of two or more pure substances. HeterogeneousHomogeneous

Mixtures Solution –homogeneous –very small particles –no Tyndall effect Tyndall Effect –particles don’t settle –EX: rubbing alcohol

Mixtures Colloid –heterogeneous –medium-sized particles –Tyndall effect –particles don’t settle –EX: milk

Mixtures Suspension –heterogeneous –large particles –Tyndall effect –particles settle –EX: fresh-squeezed lemonade

Mixtures Examples: –mayonnaise –muddy water –fog –saltwater –Italian salad dressing colloid suspension colloid solution suspension

Classification of Matter MATTER (gas. Liquid, solid, plasma) PURE SUBSTANCES MIXTURES HETEROGENEOUS MIXTURE HOMOGENEOUS MIXTURES ELEMENTSCOMPOUNDS Separated by physical means into Separated by chemical means into

Classification of Matter uniform properties? fixed composition? chemically decomposable? no yes hetero- geneous mixture solution element compound

Elements, Compounds, and Mixtures (a) an element (hydrogen) (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) hydrogen atoms hydrogen atoms oxygen atoms

Compounds vs. Mixtures Compounds have properties that are uniquely different from the elements from which they are made. –A formula can always be written for a compound –e.g. NaCl  Na + Cl 2 Mixtures retain their individual properties. –e.g. Salt water is salty and wet

Diatomic Elements, 1 and 7 H2H2 N2N2 O2O2 F2F2 Cl 2 Br 2 F2F2

Top Ten Elements in the Universe Percent Element (by atoms) 1.Hydrogen Helium Oxygen Carbon Neon Iron Nitrogen Silicon Magnesium Sulfur A typical spiral galaxy (Milky Way is a spiral galaxy)

The Composition of Air Air Nitrogen Oxygen Helium Water vapor Water vapor Neon Carbon dioxide Carbon dioxide Argon