Unit 1. Matter and Change

Do Now: What are the parts of the scientific method and explain each part?

Objective Identify the common steps of scientific methods Identify types of variables Describe the difference between a theory and a scientific law Identify the characteristics of a substance Distinguish between physical and chemical properties Differentiate among the physical states of matter

Objectives Continued Activities: Define physical and chemical changes and list common changes Apply the law of conservation of mass to chemical reactions Activities: Q&A Solve problems Exit Ticket

Scientific Method (p12) Systematic approach used in scientific study Method for scientists to verify the work of others

Steps of Scientific Method Observation Hypothesis Experiments Conclusion Theory/ Scientific Law

Observation Act of gathering information Qualitative Data- color, shape, odor other physical characteristics Quantitative Data – some type of measurement. It is numerical. Ex. Height, weight, how fast, how slow etc.

Hypothesis Tentative explanation for what has been observed.

Experiment Set of controlled observations used to test the hypothesis Must carefully plan and set up one or more laboratory experiments in order to change and test one variable at a time. Independent Variable – Variable that you plan to change. ( what you can control) Dependent Variable – variable that changes based on the independent variable

Conclusion Judgment based on the information obtained

I. Kinetic Molecular Theory States of Matter Ch. 3 - Matter I. Kinetic Molecular Theory States of Matter

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

Three States of Matter Solids very low KE - particles vibrate but can’t move around fixed shape fixed volume

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

Three States of Matter Gases high KE - particles can separate and move throughout container variable shape variable volume Vapor- Gaseous state of a substance that is a solid or liquid at room temperature.

Matter and its Properties It’s Classified!

Physical vs. Chemical Physical Property Chemical Property can be observed without changing the identity of the substance Extensive or intensive properties Chemical Property describes the ability of a substance to undergo changes in identity

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.-

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

Physical vs. Chemical Physical Change Chemical 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

Signs of a Chemical change in color or odor formation of a gas formation of a precipitate (solid) change in light or heat

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

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

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

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

Law of Conservation of Mass Mass is neither created nor destroyed during a chemical reaction. It is conserved In a chemical reaction, the mass of the reactants must equal the mass of the products

Law of Conservation of Mass Pg. 78 #7 A student carefully placed 15.6 g of sodium in a reactor supplied with an exess quantity of chlorine gas. When the reaction was complete, the student obtained 39.7f of sodium chloride. Calculate how many grams of chlorine gas reacted. How many grams of sodium reacted?

Law of Conservation of Mass Pg. 78 #7 A student carefully placed 15.6 g of sodium in a reactor supplied with an exess quantity of chlorine gas. When the reaction was complete, the student obtained 39.7f of sodium chloride. Calculate how many grams of chlorine gas reacted. How many grams of sodium reacted? 24.1 g of chlorine gas, 15.6 of sodium

Law of Conservation of Mass Pg. 78 #7 A student carefully placed 15.6 g of sodium in a reactor supplied with an exess quantity of chlorine gas. When the reaction was complete, the student obtained 39.7f of sodium chloride. Calculate how many grams of chlorine gas reacted. How many grams of sodium reacted? 24.1 g of chlorine gas, 15.6 of sodium

HW Pg 79 (10 and 13 only)

Do Now: DO NOW: What is a solution? Describe the difference between a heterogeneous and homogenous mixture Calculate % by Mass

Objective: SWBAT: Activities Contrast Mixtures and substances Classify mixtures as homogeneous or heterogeneous List and describe several techniques used to separate mixtures. Distinguish between elements and compounds Activities Q&A Solve problems Exit Ticket

Objective: Activities:

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

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

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

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.

Two different compounds, each has a definite composition. 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, O2, S8 Compounds Made of elements that are chemically joined Can be broken down NaCl, H2O, AlCl3, H2SO4

Diatomic Elements Hydrogen Nitrogen Oxygen Fluorine Chlorine Bromine Iodine There are 7 diatomic elements These atoms are never alone, if they are the pair up with the same atom

C. Mixtures Variable combination of 2 or more pure substances. Heterogeneous Homogeneous

C. Mixtures Solution homogeneous very small particles no Tyndall effect Tyndall Effect

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

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

Tea – Homogeneous Mixture

Air – Homogeneous Mixture

Alloys – Homogeneous Mixtures

Cereal – Heterogeneous Mixture

Sand – Heterogeneous Mixture

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

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

% by Mass = Percent by Mass AKA % composition

Example P 88 # 19 A 78.0 g sample of an unknown compounds contains 12.4 g of hydrogen. What is the present by mass of hydrogen in the compound?

Example P 88 # 19 A 78.0 g sample of an unknown compounds contains 12.4 g of hydrogen. What is the present by mass of hydrogen in the compound? % mass = (12.4/78.0) * 100 = 15.9%

Extra problems: Pg 88 (# 22-23)

HW Pg 90 (28) Pg 94 (32, 37, 38, 40, 42, 43,44,50,52, 57,58,60, 62, 64, 76, 92)

Do Now: Look at your periodic table. What important information can you get from the PTOE?

Objectives Activities Find patterns in the Periodic Table Classify elements as metals, non-metals or metalloids Distinguish between metals, non-metals or metalloids Activities PPT Group work

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

How PTOE is organized Metals Nonmetals Metalloids C. Johannesson

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

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 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). 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 Vary greatly in appearance Non-lustrous 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: H2(g) N2(g) O2(g) F2(g) Cl2(g) Br2(l) I2(l) (volatile liquid - evaporates readily) 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.

Exit Ticket: Classify the following as either a METAL, NON-METAL or METALLOID: Au Si Br An element that is brittle and conducts electricity An element that is malleable An element that has tendency to become an anion

Review of Unit List topics we have covered. Study for test!