Chemistry – The Study of Matter Alchemists hard at work.

Chemistry The study of the composition, structure, and properties of matter and the changes it undergoes. Branches: Organic Inorganic Physical Analytical Biochemistry Theoretical

Research – What are some ‘modern technologies’ that have impacted the way we live? Basic Reasearch Increasing knowledge Applied Research Solve a specific problem Technological Development Production and use of products to improve quality of life

Matter 4 states of matter Kinetic Molecular Theory (KMT) Solids Liquids Gases Plasma Kinetic Molecular Theory (KMT) All matter is made of particles that are in constant motion

Solids Very low KE – particles vibrate Fixed shape Fixed volume

Liquids Low KE – particles can move around but are close together Variable shape Fixed volume

Gases High KE – particles separate and move freely Variable shape Variable volume

Plasma Very high KE Gas-like – variable shape and volume particles collide with enough energy to break into charged particles Gas-like – variable shape and volume Ex: stars, fluorescent light bulbs

The Four States of Matter Solid, Liquid, Gas, and Plasma

Phases of Matter

Intensive v. Extensive Properties Intensive property does NOT depend on sample size. Ex: density, melting point Extensive property does depend on sample size. Ex: mass, volume, energy

Physical Properties and Changes Can be observed without changing the identity of the substance Examples: Color Viscosity Melting and boiling points Thermal conductivity Electrical conductivity More Examples: Specific heat Luster State of matter Phase changes Magnetism Solubility Malleability Ductility Crystal Form Tenacity

Chemical Properties and Changes Ability to change into a new substance Reactants become products Examples: Flammable Rusting Reactivity Oxidation Acidity/basisity Corrosion Inert

Chemical and Physical Properties

All chemical and physical changes involve ENERGY!!!

Signs of a Chemical Change ๏ change in color or odor ๏ formation of a gas ๏ formation of a precipitate (solid) ๏ production of light ๏ absorption or release of heat

Name that property Honey and motor oil are very slow to pour. What property bests describes this property??? Viscosity What property of liquids would you look for to start charcoal for a BBQ???? Flammability Iron heats up faster than aluminum. What property is this???? Specific Heat

Name that property (more) Paints made of silver are applied to the back of mirrors. What property of silver is useful???? Luster The copper on the Statue of Liberty has turned green. What property is causing this??? Corrosion or Oxidation Jewelry can be pounded to form artistic designs. What property is this???? Malleability

Name that property (still) A good frying pan heats food evenly. What property of frying is this???? Thermal Conductivity Quartz forms hexagons and diamonds form cubes. What property is this??? Crystal Form You purchase a clear stone that might be a diamond. What simple test can you make to determine if it is actually a diamond??? Hardness

Name that property (lastly) You accidentally drop an iron bolt into a hard-to-reach place in your automobile engine. What property of iron enables you to retrieve the bolt without having to find someone with small hands? Magnetism

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

Solid Gas Liquid Melting Deposition Freezing Sublimation Condensation Evaporation

Energy & Phase Changes Heat of vaporization - Amount of heat needed to change a liquid into a gas at its boiling point Heat of fusion - Amount of heat required to melt a solid at its melting point

Phase Change Diagram Show the changes of state for any subs. Show the temperatures where the phase change occurs Is more energy used to convert ice to water or water to steam?

Insert phase diagram on p. 49

Classification Flowchart Homogeneous Mixture (solution) Is the composition uniform? no yes MATTER Can it be physically separated? Heterogeneous Mixture Compound Element MIXTURE PURE SUBSTANCE Can it be chemically decomposed? Colloids Suspensions

Classification of Matter Examples: Graphite Pepper Sugar (sucrose) Paint Soda Element Heterogeneous mixture Compound Solution (homogeneous mixture

Pure Substances Element Composed of identical atoms Ex: Copper wire, aluminum foil

Pure Substances Compounds C H O Composed of two or more elements in a fixed ratio Properties differ from individual elements Ex: glucose, caffeine

Mixtures Combination of 2 or more pure substances Homogeneous mixtures Colloids Suspensions Heterogeneous mixtures

Mixtures Homogeneous AKA: Solution Very small particles that do not settle No Tyndall effect Ex: rubbing alcohol, salt water

Liquid Mixtures Miscible – liquids are able to dissolve into each other Homogeneous mixture of liquids Gasoline = homo. mixture of 100 compounds Immiscible – liquids are NOT able to dissolve into one another Heterogeneous mixture of liquids Oil and water will not mix

Mixtures Colloid Heterogeneous Medium sized particles that do NOT settle Tyndall effect Ex: milk

Colloids scatter light, making a beam visible. Which glass contains a colloid? solution colloid Colloids scatter light, making a beam visible.

Smoke, airborne bacteria Solid Examples of Colloids Dispersing Medium Dispersed Substance Colloid Type Fog, aerosol sprays Gas Liquid Aerosol Smoke, airborne bacteria Solid Whipped cream, soap suds Foam Milk, mayonnaise Emulsion Paint, clays, gelatin Sol Marshmallow, Styrofoam Solid foam Butter, cheese Solid emulsion

Mixtures Suspension Heterogeneous Large particles that will settle Tyndall effect Ex: fresh squeezed lemonade

Mixtures – Colloid, suspension, or solution?? Examples Mayonnaise Muddy water Fog Salt water Italian salad dressing Colloid Suspension Solution

The Periodic Table Rows – Periods Columns – Groups or Families Three main types of elements Metals Nonmetals Metalloids

Metals Conducts heat and electricity Malleable Ductile

Nonmetals Many are gases at room temperature Solids are brittle

Metalloids Touch the stair-step line (except Al) Some characteristics of metals and nonmetals Semiconductors