Ch. 2 - Matter Properties & Changes in Matter  Extensive vs. Intensive  Physical vs. Chemical

A. Extensive vs. Intensive  Extensive Property  depends on the amount of matter present  Intensive Property  depends on the identity of substance, not the amount

A. Extensive vs. Intensive  Examples:  boiling point  volume  mass  density  conductivity intensive extensive intensive

B. Physical vs. Chemical  Physical Property  can be observed without changing the identity of the substance  Chemical Property Chemical Property  describes the ability of a substance to undergo changes in identity

B. Physical vs. Chemical  Examples:  melting point  flammable  density  magnetic  tarnishes in air physical chemical physical chemical

B. Physical vs. Chemical  Physical Change  changes the form of a substance without changing its identity  properties remain the same  Chemical Change  changes the identity of a substance  products have different properties

B. Physical vs. Chemical  Signs of a Chemical Change  change in color or odor  formation of a gas  formation of a precipitate (solid)  change in light or heat

B. Physical vs. Chemical  Examples:  rusting iron  dissolving in water  burning a log  melting ice  grinding spices chemical physical chemical physical

C. Matter  Law of Conservation of Matter  Antoine Lavoisier (1700’s)  Like energy, matter is neither created or destroyed in any process –For example, a burning candle burning fire wood (products are gases and ashes) – mass before = mass after

C. Matter Law of Definite Composition  A given compound always contains the same, fixed ratio of elements.  H 2 O is not H 2 O 2 Law of Multiple Proportions  Elements can combine in different ratios to form different compounds. Chem/phys HO

A. Matter Flowchart 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

B. Pure Substances  Element  composed of identical atoms  can’t be separated by physical or chemical means  EX: copper wire, aluminum foil

B. Pure Substances  Compound  composed of 2 or more elements in a fixed ratio  properties differ from those of individual elements  EX: table salt (NaCl) Water ( H 2 O)

C. Mixtures  Solution  homogeneous  very small particles  no Tyndall effect Tyndall Effect  particles don’t settle  EX: rubbing alcohol sugar water

C. Mixtures  Colloid  heterogeneous  medium-sized particles  Tyndall effect  particles don’t settle  EX: milk

C. Mixtures  Suspension  heterogeneous  large particles  Tyndall effect  particles settle  EX:fresh-squeezed lemonade

D. Examples  Examples:  graphite  pepper  sugar (sucrose)  paint  soda element hetero. mixture compound Suspension (hetero) Solution (homog.)

D. Examples of Mixtures  Examples:  mayonnaise  muddy water  fog  saltwater  Italian salad dressing colloid suspension colloid solution suspension

Define and Explain these methods of Separation in your notes -  Filtration –  Magnetism –  Crystallization –  Chromatography –  Distillation –  Electrolysis-  Decanting-  Centrifuge-  Evaporation-

A. Energy  Energy – the capacity to do work or produce heat. Work is the capacity to move an object over a distance against a force; For example: it moves cars, bakes a cake, keeps ice frozen, lights houses, etc.  Two Kinds:  Kinetic – energy of motion (waves, molecules, objects)  Potential – stored energy or energy of position in the chemical bonds

A. Energy  Forms of energy: 1.Kinetic energy: Electrical Radiant Thermal Motion Sound 2. Potential energy Chemical Stored mechanical Nuclear Gravitational

A. Energy  Law of Conservation of Energy:  energy is neither created nor destroyed  When we use energy, it doesn’t disappear  It can be changed from one form to another:  1).A car burns gasoline, converting the chemical energy into mechanical energy 2). Solar cells change radiant energy into electrical energy

B Temperature  Heat or thermal energy, is the total random kinetic energy of the particles.  Heat flows from a hot object to a cold object. For example: can of soda  Temperature – measure of the average random kinetic energy of the particles. Temperature – measure of the average random kinetic energy of the particles.

B Temperature  SI unit of temp: Kelvin (K)  The zero point on the Kelvin scale is called absolute zero (the point at which the motion of particles ceases). 0 K = o C ( no degree symbol and no negative numbers on the Kelvin scale because there is no negative motion! )

B Temperature  Formulas: o C = K – 273 or K = o C Examples: 1.Antifreeze boils at 197 o C. Convert to Kelvin. 2.Normal body temp is 310 K. Convert to Celsius K o C

C Energy Units  SI unit of energy: joule (J)  calorie (cal) : another unit of energy  1 cal = amount of heat needed to raise the temperature of 1g of water, 1 o C.

C Energy Units  1 cal does not equal 1 Cal !  Calorie (capital C) is the energy stored in food! 1 Cal = 1000 cal So 200 Cal supplies 200,000 cal of energy! Conversion factors: 1 cal = J 1 Cal = KJ

C Energy Units Using dimensional analysis: 3. Convert 540 cal to KJ

D Metric prefixes  4. Convert 598 g to pg.  5. Convert 598 pg to Gg.