Unit_1_20041

Unit 1: Properties of Matter Chapter 2

Objective 1• Demonstrate a clear

understanding of the safety rules for the chemistry classroom.

Handout Safety Rules• Read and study for homework.• Your teacher will demonstrate and

discuss safety procedures throughout the year.

Chemistry Spring Semester Lab Policy

• Important things to remember when in a chemistry lab which can affect your grade: – Following all safety rules and precautions.– Following all written and verbal instructions.– Active participation in the scheduled lab.– Cleanliness of lab table, equipment and drawer at

the end of the lab.– Using time wisely.

Lab Policy, cont.• You will be warned one time about any

violation and you will lose points. • A second warning will result in your

removal from the lab. To receive a grade other than zero, you will have to come in and make the lab up before or after school.

Objective 2• Classify matter using a concept

map.

Objective 2, continued• Matter-takes up space and has mass.• There are three states of matter: solid,

liquid, and gas.

Classify Matter using a Concept Map

MetalsMetalloidsNonmetals

Elements Compounds

Pure Substances

Solutions

Homogeneous

SuspensionsColloids

Heterogeneous

Mixtures

Matter

Objective 3• Distinguish pure substances from

mixtures.

Objective 3• Pure substances-

matter that has the same (uniform) composition

• Mixtures- two or more substances combined.

• The composition of a mixture IS NOT fixed.

Mixture• The ingredients to

make salsa are a mixture.

• The composition is not in a fixed ratio.

• You could vary the number of tomatoes, peppers, etc.

Classify the following as a pure substance or a mixture. • Sodium• Table salt• Oxygen gas• Air• Sugar• Paint• Rubbing alcohol (70% alcohol and 30% water)• Sulfur• Dirt

Answers• Pure substances

– Sodium– Table salt– Oxygen gas– Sugar– Sulfur

– These are all elements or compounds

• Mixtures– Air– Paint– Rubbing alcohol– Dirt

– More than one substance is physically blended together.

Objective 4• Classify pure substances as elements

or compounds.

Objective 4• Pure substances-matter that always has

the same composition.• Elements and compounds are pure

substances.

Objective 4, continued• An element contains only one kind of

atom. An atom is the smallest particle of an element. Examples of elements are : gold, aluminum, carbon and iodine (these are on the periodic table).

Periodic Table• Look in the back of your book!• The periodic table has all known

elements listed.• How many elements are there?

Objective 4, continued• Compounds- two or more elements in

a fixed proportion.

Example of a compound• Sodium chloride• NaCl• Ratio 1:1

Example of a compound• Sodium

bicarbonate• NaHCO3

• Common baking soda

• 1Na:1H:1C:3O

• Pure substances are elements or compounds.

Objective 5• Describe the characteristics of an

element and the symbols used to identify elements.

Handout Symbol list.

• http://education.jlab.org/indexpages/elementgames.php– Flash cards– Hangman– Matching

• http://www.quia.com/jfc/65919.html

Objective 5, continued• Turn to the back hard cover of your

textbook. • You see from this periodic table that

there are over 110 elements. • Some occur naturally and others are

man-made. • All elements are represented by an

International System of symbols.

Objective 5, continued• The first letter is capitalized, the second

letter is lower case.• Many elements are just the first and

second letter. Some are just the first letter of the element’s name.

• Others are based on Latin, a person’s name or a place.

Objective 5, continuedHe Helium Cf CaliforniumNe Neon Ag SilverRn Radon Au GoldH Hydrogen Cm CuriumNa Sodium Md MendeleviumK Potassium Pb Plumbous (Lead)W Tungsten

Objective 6• Describe the characteristics of a

compound. – Two or more elements chemically

combined in a fixed proportion.

Objective 6, continued• Consider the elements hydrogen, H2

and oxygen, O2.

• These two elements have very different properties and can combine to produce:

Hydrogen + oxygen water

Hydrogen + oxygen hydrogen peroxide

Objective 6, continuedWater Hydrogen PeroxideH2O H2O2

2H:1O 2H:2O2 grams H, 16 g O 2 g H, 32 g OWe drink it! Cleanses wounds,

but toxic in the body

Objective 7• Classify elements as metals,

metalloids or nonmetals.

Periodic Table in Text• Metals are blue.• Metalloids are green.• Nonmetals are orange.• Find the zigzag line.• Elements “sitting” or “leaning” on stair step line are metalloids (except for aluminum).

Homework• Study safety handout.• Memorize symbol list.• Read p. 38-50 in text.• Review sheet, part I.

Warm up • Write the symbol for the following

elements:– Tungsten, silver, potassium

• Write the name for the following symbols:– Pb, P, Hg

AnswersAns. W, Ag, K Lead, Phosphorus, Mercury

Objective 8• Classify mixtures as heterogeneous or

homogeneous.

Classify Matter using a Concept Map

MetalsMetalloidsNonmetals

Elements Compounds

Pure Substances

Solutions

Homogeneous

SuspensionsColloids

Heterogeneous

Mixtures

Matter

Objective 8, continued• Heterogeneous-the parts of the

mixture are noticeably different from one another.– Not uniform in appearance– More than one phase may be present– Separated by boundaries.

Examples of Heterogeneous Mixtures• Granite rocks on the jetties of Galveston• Concrete • Soil• Wood• An orange• Vinegar and oil

Objective 8, continued• Homogeneous-the substances are so

evenly distributed that the mixture will have a uniform appearance.– All one phase– Evenly distributed

Examples of Homogeneous Mixtures• Swimming pool

water• Physiological Saline• Rubbing Alcohol• Pure air• Glass• Antifreeze• Metal alloys

Objective 9

Classify mixtures as solutions, suspensions, or colloids.

Demonstrations:• Laser Demo: Muddy water, Milk and

Copper (II) sulfate(aq)

• Demo: Chemical Sunset

Suspension• Heterogeneous• Dispersed particles are visible.• Reflects light.• Settles on standing.• Cannot pass through filter paper.• Cannot pass through animal

membrane.

Colloid• Heterogeneous• Cannot see dispersed particles.• Reflects light.• Does not settle on standing.• Can pass through filter paper.• Cannot pass through animal

membrane.

Solution• Homogeneous• Particles are molecular in size.• Does not reflect light; light passes

through.• Does not settle.• Can pass through filter paper and

an animal membrane.

Homework• Symbol quiz next time.• Quiz on matter diagram. Must be

able to write the chart from memory.

• Review Sheet, Part 2.• Bring COMPUTERS next class!

Matter Activity• Students will practice with Matter

Diagram Kit

Classify Matter using a Concept Map

MetalsMetalloidsNonmetals

Elements Compounds

Pure Substances

Solutions

Homogeneous

SuspensionsColloids

Heterogeneous

Mixtures

Matter

Objective 10• Describe and observe physical

properties of matter.

Physical Properties • All substances exhibit physical

properties.

These Physical Properties depend on the amount of matter.• Mass• Length• Volume• Total Energy content

These Physical Properties do not depend on the amount of matter.• Color• Solubility• Odor• Physical State (s, l,

g)• Hardness• Malleability• Ductility

• Density• Magnetism• Crystal Shape• Melting Point• Boiling Point• Conductivity of

heat or electricity

Physical Properties• Go tohttp://www.webelements.com

• Investigate a nonmetal, metal and metalloid.

Webelements.com• Show students the following

examples.• You have 10 minutes!• You cannot do the ones shown in

lecture.

Physical Properties of O2

• Gas at 298K• Colorless• Liquid is pale blue• It is a nonmetal• Liquid oxygen is paramagnetic• Very reactive• Melting point -218.3oC• Boiling point –182.9oC

Physical Properties of Ozone, O3

• Ozone is O3, while Oxygen is O2

• Toxic• Gas is bluish in color• Liquid ozone is bluish-black• Solid is violet-black

Physical Properties of Na• Solid at 298K• Silvery white• Metal• Density= .968 g/cm3

• Melting point 97.72oC• Boiling point 883oC

Physical Properties of Silicon• Solid at 298K• Dark gray with a bluish tinge• Metalloid or semi-metallic• Density = 2.330 g/cm3

• Melting point 1414oC• Boiling point 2900oC

Objective 11• Describe methods used to separate

mixtures.

Methods used to separate mixtures.• Filtration• Evaporation• Distillation• Physical sorting• Magnetism• Chromatography

Filtration- is a process that separates materials based on the size of their particles.

Evaporation- vaporization that occurs at the surface of a liquid that is not boiling.

Distillation- is a process that separates the substances in a solution based on their boiling points.

Physical Sorting- use a wire screen or sort particles by hand.

Magnetism- could be used to separate any ferromagnetic material in a mixture.

Chromatography- a solvent carries the molecules up paper and they are separated.

Objective 12• Describe evidence that indicates a

physical change is taking place.

Objective 12• A physical change alters the

substance without changing its composition.

Physical Change• Cutting• Grinding• Bending• Pounding• Dissolving• Changing phase

– Solid to liquid to gas

• Pouring from one container to another

Demonstration• Separation of a Mixture• Students complete report sheet

during the demonstration.

Homework• Read p. 51-58.• Review Sheet, Part 3.• You will do Lab: Chromatography

next time.

Lab Chromatography• You will have three knowns:

– Fe+3, Ni+2 and Cu+2

• You will have an unknown mixture. It consists of two of the knowns.

• You will color and record your chromatograms before and after developing.

• Analyze your data and identify what is in your unknown.

Warm up• What color is a solution containing

Ni+2?• Which ion had a blue color on the

chromatogram?• Which ion was yellow?• Why was developing necessary?

Objective 13• Describe chemical properties of matter.

Objective 13, continued• A chemical property is any ability to

produce a change in the composition of matter.

• Chemical properties are usually observed.

Chemical Properties• Gasoline is flammable.• Oxygen reacts with hydrogen.• Nitrogen has low reactivity.• Potassium reacts with water to

produce hydrogen gas.• Zinc reacts actively with acid.

Objective 14Describe clues that indicate that a chemical change is taking place.

A chemical change occurs when a substance reacts and forms one or more new substances.

Objective 14• There are four evidences that you look

for to see if a chemical change has occurred: – Change in color.– Production of a gas.– Formation of a precipitate (solid formed

from liquids).– Change in energy.

Change in color.

Production of a gas.

Formation of a precipitate.

Change in energy.

Objective 15Distinguish chemical changes from physical changes.

Objective 15• A chemical

change will form new products with different properties.

• In a physical change you still have the same substance.

Demonstration Evidence of Chemical Reaction• Color Change• Formation of a Precipitate• Production of a Gas• Energy Change

Careers that involve the study of matter.• Mining, refining,

disposal and recycling of raw materials

• Developing the science of metals

• Polymers• ceramics

• Glasses• Electronic

materials• Biomedical

materials

Homework• Review Sheet, Part 4.

Lab Physical and Chemical Change• Work carefully in groups. • Make detailed observations.• Homework: finish lab report and

study for test.

The end.