Unit 1. Matter and Change Chapter 1 and 3

Do Now:  What is matter as described in Chemistry?

Chapter 1 & 3 Objective  Distinguish between:  intensive and extensive properties  Physical & chemical changes/properties  Classify matter

Matter and its Properties  It’s Classified!  But first what is Scientific Method and what does it involve?

Properties & Changes in Matter  Extensive vs. Intensive  Physical vs. Chemical

A. Extensive vs. Intensive  Extensive Property  depends on the amount of matter present  ex,.-  Intensive Property  depends on the identity of substance, not the amount  Ex.-

A. Extensive vs. Intensive  Extensive Property  depends on the amount of matter present  ex,.- Volume, mass, Energy  Intensive Property  depends on the identity of substance, not the amount  Ex.- melting point, boiling point, conduct electricity or heat  WHAT ABOUT DENSITY??

A. Extensive vs. Intensive  Examples:  boiling point  volume  mass  density  conductivity

A. Extensive vs. Intensive  Examples:  boiling point…… intensive  Volume …. extensive  Mass ….. extensive  Density ….. intensive  Conductivity ….. intensive

PROPERTY B. Physical vs. Chemical  Physical Property  can be observed without changing the identity of the substance  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

CHANGE C. 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

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

In the example of burning of charcoal, carbon and oxygen are the reactants in the combustion reaction. Carbon dioxide is the product. carbon + oxygen carbon dioxide C + O2 CO2 (reactants) (product) Properties and Changes in Matter

Homework  Review Scientific Method: Read page 12 – 16 Q 17 Complete - Work sheet

STATE OF MATTER Chapter 3

Do Now  Name the State of Matter  How do they differ?

States of Matter  There are Four state of matter  A. Solid  B. Liquid  C. Gas  D. Plasma  State of matter depends on Kinetic Energy between the particles

A. Kinetic Molecular Theory  KMT  Particles of matter are always in motion.  The kinetic energy (speed) of these particles increases as temperature increases.

Four States of Matter  A. Solids  very low KE - particles vibrate but can’t move around  fixed shape  fixed volume

Four States of Matter  B. Liquids  low KE - particles can move around but are still close together  variable shape  fixed volume

Four States of Matter  C. Gases  high KE - particles can separate and move throughout container  variable shape  variable volume

Four States of Matter  D. Plasma  very high KE - particles collide with enough energy to break into charged particles (+/-)  gas-like, variable shape & volume  stars, fluorescent light bulbs, CRTs

SOLUTIONS AND MIXTURES

Objective:  Classification of Matter  DO NOW:  What is a solution?  Describe the difference between a heterogeneous and homogenous mixture

A. Pure Substances  Element  composed of identical atoms  EX: copper wire, aluminum foil

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

A. 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.

A. Pure Substances  For example… Two different compounds, each has a definite composition.

Pure Substances (constant composition)  Elements  Listed on the Periodic Table  Cannot be broken down into unique components  Na, Cl, Al, O 2, S 8  Compounds  Made of elements that are chemically joined  Can be broken down  NaCl, H 2 O, AlCl 3, H 2 SO 4

B. Mixtures  Variable combination of 2 or more pure substances. HeterogeneousHomogeneous

B. Mixtures (variable composition)  Homogeneous – Solutions  evenly distributed  Heterogeneous  not evenly distributed

B. Mixtures  Solution  homogeneous  very small particles  no Tyndall effect Tyndall Effect

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

B. Mixtures  Suspension  heterogeneous  large particles  Tyndall effect  particles settle  EX: fresh-squeezed lemonade

C. Mixtures  Examples:  mayonnaise  muddy water  fog  saltwater  Italian salad dressing

C. Mixtures  Examples:  mayonnaise  muddy water  fog  saltwater  Italian salad dressing colloid suspension colloid solution suspension

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

A. Matter Flowchart  Examples:  graphite  pepper  sugar (sucrose)  paint  soda

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

Tea – Homogeneous Mixture

Air – Homogeneous Mixture

Alloys – Homogeneous Mixtures

Cereal – Heterogeneous Mixture

Sand – Heterogeneous Mixture

Separating Mixtures Only a physical change- no new matter  Filtration - separate solids from liquids with a barrier (filter paper)  Distillation - separate liquids because of different boiling points  Heat mixture  Catch vapor in cooled area  Chromatography - different substances are attracted to paper or gel, so move at different speeds

Separating Mixtures cont….  Crystallization - results in formation of solid particles of a substance from a solution containing the dissolved substance  Sublimation – separation when a solid changes to a vapor without melting or going through a liquid phase

Filtration Distillation Chromatography

 d. Crystallization e. Sublimation Ex: rock candyEx: Dry Ice

Homework  Pg 83 – Q 15, 17  Pg 94 & 95 – Q 42, 43, 48, 58, 63

The Periodic Table

A. Mendeleev  Dmitri Mendeleev (1869, Russian)  Organized elements by increasing atomic mass.  Elements with similar properties were grouped together.  There were some discrepancies. C. Johannesson

A. Mendeleev  Dmitri Mendeleev (1869, Russian)  Predicted properties of undiscovered elements. C. Johannesson

B. Moseley  Henry Moseley (1913, British)  Organized elements by increasing atomic number.  Resolved discrepancies in Mendeleev’s arrangement. C. Johannesson

II. Organization of the Elements

A. Metallic Character  Metals  Nonmetals  Metalloids C. Johannesson

B. Blocks  Main Group Elements  Transition Metals  Inner Transition Metals C. Johannesson

Do Now:  Classify the following as either a METAL, NON-METAL or METALLOID: a. Au b. Si c. Br

Periods and Families  Periods: horizontal rows on the periodic table  physical and chemical properties change somewhat regularly across a row.  Elements closer to each other in the same period tend to be similar properties than those that are farther apart.  Families: vertical rows of elements, aka groups  Each group contains similar chemical properties

Types of Elements  METALS:  Shiny  Conductors of heat and electricity  Most metals are malleable (can be pounded into thin sheets; a sugar cube sized chunk of gold can be pounded into a thin sheet which will cover a football field),  Most metals are ductile (can be drawn out into a thin wire).

Metals cont…..  All are solids at room temp (except Mercury, which is a liquid)  Metals tend to have low ionization energies, and typically lose electrons (i.e. are oxidized) when they undergo chemical reactions  Alkali metals are always 1+ (lose the electron in s subshell)  Alkaline earth metals are always 2+ (lose both electrons in s subshell)  Compounds of metals with non-metals tend to be ionic in nature.

Types of Elements  NON- METALS:  Vary greatly in appearance  Non-lustrous  Poor conductors of heat and electricity  The melting points of non-metals are generally lower than metals  Seven non-metals exist under standard conditions as diatomic molecules: H 2 (g) N 2 (g) O 2 (g) F 2 (g) Cl 2 (g) Br 2 (l) I 2 (l) (volatile liquid - evaporates readily)

Non-Metals cont……..  Nonmetals, when reacting with metals, tend to gain electrons (typically attaining noble gas electron configuration) and become anions: Nonmetal + Metal -> Salt  Compounds composed entirely of nonmetals are molecular substances (not ionic)

Types of Elements  Metalloids:  Elements may share properties of metals and non-metals.  A stair-step line separates the metals from the nonmetals on the periodic table.

Metalloids  Properties:  All metalloids are solids at room temperature.  Less malleable than metals but not as brittle as nonmetals.  Metalloids tend to be semiconductors of electricity. (intermediate between metals and nonmetals).

Metalloids  Properties:  Metalloids are used in semiconducting materials found in computers, calculators, televisions and radios.  Elements include: boron, silicon, germanium, antimony

Noble Gases  Noble Gases - the elements in Group 18 of the periodic table.  They are considered nonmetals.  These elements are generally unreactive.  All are gases at room temperature.  Examples: neon, argon, krypton, xenon (all used in lighting) and helium.

DO NOW: Name an element that is: a. An element that is brittle and conducts electricity b. An element that is malleable c. An element that has tendency to become an anion

Group Practice  Look at Page 95 – Insert Questions

Law of Conservation of Matter:  Matter is neither created nor destroyed.  Since chemical reactions cannot create or destroy atoms, chemical equations representing the reactions must always be BALANCED.  Mass reactants = Mass products

% by Mass of Substance Mass of Element  Percent by mass =X 100 Mass of Compound