Chapter 2Chapter 2

Science, Systems, Science, Systems, Matter, and EnergyMatter, and Energy

TYPES AND STRUCTURE OF TYPES AND STRUCTURE OF MATTERMATTER

Elements and CompoundsElements and Compounds Matter exists in chemical forms as elements and Matter exists in chemical forms as elements and

compounds.compounds.• Elements (represented on the periodic table) are the Elements (represented on the periodic table) are the

building blocks of matter.building blocks of matter.• Compounds: two or more different elements held Compounds: two or more different elements held

together in fixed proportions by chemical bonds.together in fixed proportions by chemical bonds.

Basic ChemistryBasic Chemistry Matter, Mass, and WeightMatter, Mass, and Weight

MatterMatter: Anything that occupies space and : Anything that occupies space and has masshas mass

MassMass: The amount of matter in an object: The amount of matter in an object Weight:Weight: The gravitational force acting on The gravitational force acting on

an object of a given massan object of a given mass Elements and AtomsElements and Atoms

Elements:Elements: The simplest type of matter with The simplest type of matter with unique chemical propertiesunique chemical properties

Atoms:Atoms: Smallest particle of an element that Smallest particle of an element that has chemical characteristics of that elementhas chemical characteristics of that element

AtomsAtoms

Figure 2-4Figure 2-4

Atomic StructureAtomic Structure AtomsAtoms: composed of : composed of

subatomic particlessubatomic particles Neutrons: no electrical Neutrons: no electrical

chargecharge Protons: positive chargeProtons: positive charge Electrons: negative Electrons: negative

chargecharge

NucleusNucleus Formed by protons and Formed by protons and

neutronsneutrons Most of volume of atom Most of volume of atom

occupied by electronsoccupied by electrons

Atomic Number and Mass NumberAtomic Number and Mass Number Atomic NumberAtomic Number: Equal to number of protons in : Equal to number of protons in

each atom which equals the number of electronseach atom which equals the number of electrons Mass NumberMass Number: Number of protons plus number of : Number of protons plus number of

neutronsneutrons

Isotopes and Atomic MassIsotopes and Atomic Mass Isotopes:Isotopes: Two or more forms of same element Two or more forms of same element

with same number of protons and electrons but with same number of protons and electrons but different neutron numberdifferent neutron number 3 types of hydrogen3 types of hydrogen Denoted by using symbol of element preceded by mass Denoted by using symbol of element preceded by mass

number as number as 11H, H, 22H, H, 33HH

Atomic Mass:Atomic Mass: Average mass of naturally occurring Average mass of naturally occurring isotopesisotopes

Molecules and CompoundsMolecules and Compounds Molecules:Molecules: Two or more atoms form a Two or more atoms form a

covalent bondcovalent bond Example: WaterExample: Water

Compounds:Compounds: A substance composed of A substance composed of two or more different types if atoms two or more different types if atoms chemically combinedchemically combined Example: Hydrogen MoleculeExample: Hydrogen Molecule

Molecular Mass:Molecular Mass: Determined by adding Determined by adding up atomic masses of its atoms or ionsup atomic masses of its atoms or ions Example: NaCl (22.99 + 35.45)Example: NaCl (22.99 + 35.45)

Covalent BondingCovalent Bonding

AtomsAtoms share one or share one or more pairs of electronsmore pairs of electrons Single covalent:Single covalent: Electron Electron

pair between 2 atomspair between 2 atoms Double covalent:Double covalent: Two Two

atoms share 4 electronsatoms share 4 electrons

Nonpolar Nonpolar covalent: covalent: Electrons Electrons sharedshared equallyequally

Polar Polar covalent: covalent: Electrons Electrons not sharednot shared equallyequally

Electrons and Chemical BondingElectrons and Chemical Bonding Ion:Ion: When an atom loses or gains electrons When an atom loses or gains electrons

and become chargedand become charged Cation:Cation: Positively charged ion Positively charged ion Anion:Anion: Negatively charged ion Negatively charged ion

Ionic BondingIonic Bonding Cations and anions are Cations and anions are attracted attracted to each otherto each other

IonsIons

An ion is an atom or group of atoms with one An ion is an atom or group of atoms with one or more net positive or negative electrical or more net positive or negative electrical charges.charges.

The number of positive or negative charges The number of positive or negative charges on an ion is shown as a superscript after the on an ion is shown as a superscript after the symbol for an atom or group of atoms symbol for an atom or group of atoms Hydrogen ions (HHydrogen ions (H++), Hydroxide ions (OH), Hydroxide ions (OH--)) Sodium ions (NaSodium ions (Na++), Chloride ions (Cl), Chloride ions (Cl--))

Compounds and Chemical FormulasCompounds and Chemical Formulas

Chemical formulas are shorthand ways to Chemical formulas are shorthand ways to show the atoms and ions in a chemical show the atoms and ions in a chemical compound. compound. Combining Hydrogen ions (HCombining Hydrogen ions (H++) and Hydroxide ) and Hydroxide

ions (OHions (OH--) makes the compound H) makes the compound H22O O

(dihydrogen oxide, a.k.a. water).(dihydrogen oxide, a.k.a. water). Combining Sodium ions (NaCombining Sodium ions (Na++) and Chloride ions ) and Chloride ions

(Cl(Cl--) makes the compound NaCl (sodium chloride ) makes the compound NaCl (sodium chloride a.k.a. salt).a.k.a. salt).

Synthesis and Decomposition Synthesis and Decomposition ReactionsReactions

Synthesis ReactionsSynthesis Reactions Two or more Two or more

reactants chemically reactants chemically combine to form a combine to form a larger productlarger product

Decomposition Decomposition ReactionsReactions Reverse of synthesis Reverse of synthesis

reactionsreactions

Acids and Bases; Salts and BuffersAcids and Bases; Salts and Buffers

Acid:Acid: A proton donor or any substance A proton donor or any substance that releases hydrogen ionsthat releases hydrogen ions

Bases:Bases: A proton acceptor or any A proton acceptor or any substance that binds to or accepts substance that binds to or accepts hydrogen ionshydrogen ions

Buffers:Buffers: Able to maintain the pH Able to maintain the pH

The pH ScaleThe pH Scale Refers to the Refers to the

Hydrogen ion Hydrogen ion concentrationconcentration in a in a solutionsolution Neutral:Neutral: pH of 7 or pH of 7 or

equal hydrogen and equal hydrogen and hydroxide ionshydroxide ions

Acidic:Acidic: a greater a greater concentration of concentration of hydrogen ionshydrogen ions

Alkaline or basic:Alkaline or basic: a a greater concentration greater concentration of hydroxide ionsof hydroxide ions

The pH (potential of Hydrogen) is the The pH (potential of Hydrogen) is the concentration of hydrogen ions in one liter of concentration of hydrogen ions in one liter of solution.solution.

Figure 2-5Figure 2-5

ChemistryChemistry

Inorganic Chemistry:Inorganic Chemistry: Generally substances Generally substances that do not contain carbonthat do not contain carbon WaterWater OxygenOxygen

Organic Chemistry:Organic Chemistry: Study of carbon- Study of carbon-containing substancescontaining substances

Organic Compounds: Carbon RulesOrganic Compounds: Carbon Rules

Organic compounds contain carbon atoms Organic compounds contain carbon atoms combined with one another and with various combined with one another and with various other atoms such as Hother atoms such as H++, N, N++, or Cl, or Cl--..

Contain at least two carbon atoms combined Contain at least two carbon atoms combined with each other and with atoms.with each other and with atoms. Methane (CHMethane (CH44) is the only exception.) is the only exception. All other compounds are All other compounds are inorganicinorganic..

Organic ChemistryOrganic Chemistry CarbohydratesCarbohydrates

Composed of carbon, hydrogen, oxygenComposed of carbon, hydrogen, oxygen

LipidsLipids Composed mostly of carbon, hydrogen, oxygenComposed mostly of carbon, hydrogen, oxygen

ProteinsProteins Composed of carbon, hydrogen, oxygen,nitrogenComposed of carbon, hydrogen, oxygen,nitrogen

Nucleic Acids: DNA and RNANucleic Acids: DNA and RNA Composed of carbon, hydrogen, oxygen, nitrogen, phosphorusComposed of carbon, hydrogen, oxygen, nitrogen, phosphorus

Adenosine Triphosphate (ATP)Adenosine Triphosphate (ATP) Composed of adenosine and three phosphate groupsComposed of adenosine and three phosphate groups

CarbohydratesCarbohydrates

Monosaccharides or building blocksMonosaccharides or building blocks Simple sugars: glucose, fructose, galactoseSimple sugars: glucose, fructose, galactose

DisaccharidesDisaccharides Two simple sugars bound together by Two simple sugars bound together by

dehydration: sucrose, lactose, maltosedehydration: sucrose, lactose, maltose PolysaccharidesPolysaccharides

Long chains of many monosaccharides: Long chains of many monosaccharides: glycogen in animals; starch and cellulose in glycogen in animals; starch and cellulose in plantsplants

LipidsLipids Lipids:Lipids: Can be dissolved in nonpolar organic Can be dissolved in nonpolar organic

solvents as alcohol or acetone but relatively solvents as alcohol or acetone but relatively insoluble in waterinsoluble in water Fats, Oils and Waxes.Fats, Oils and Waxes. Triglycerides:Triglycerides: composed of glycerol and fatty composed of glycerol and fatty

acidsacids Phospholipids:Phospholipids: Important structural component Important structural component

of cell membranesof cell membranes Steroids:Steroids: Cholesterol, bile salts, estrogen, Cholesterol, bile salts, estrogen,

testosteronetestosterone Fat-soluble VitaminsFat-soluble Vitamins

ProteinsProteins Amino acids:Amino acids: The building blocks of protein The building blocks of protein Peptide bonds:Peptide bonds: Covalent bonds formed Covalent bonds formed

between amino acids during protein synthesisbetween amino acids during protein synthesis StructureStructure

Primary, secondary, tertiary, quartenaryPrimary, secondary, tertiary, quartenary Enzymes:Enzymes: Protein catalysts Protein catalysts

Lock-and-key modelLock-and-key model Active siteActive site CoenzymesCoenzymes

Protein Structure and Enzyme ActionProtein Structure and Enzyme Action

Nucleic Acids: DNA and RNANucleic Acids: DNA and RNA DNA: Deoxyribonucleic acidDNA: Deoxyribonucleic acid

Genetic materialGenetic material of cells of cells copiedcopied from one from one generation to nextgeneration to next

Composed of Composed of 2 strands of nucleotides2 strands of nucleotides• Each nucleotide contains one of the organic Each nucleotide contains one of the organic

bases of bases of adenine or guanineadenine or guanine which are purines which are purines and and thymine or cystosinethymine or cystosine which are pyrimidines which are pyrimidines

RNA: Ribonucleic acidRNA: Ribonucleic acid Similar to a single strand of DNASimilar to a single strand of DNA

• Four different nucleotides make up organic bases Four different nucleotides make up organic bases except except thymine is replaced with uracilthymine is replaced with uracil (pyrimidine) (pyrimidine)

DNA StructureDNA Structure

WaterWater InorganicInorganic Stabilizes body temperatureStabilizes body temperature ProtectionProtection NecessaryNecessary for many chemical reactions for many chemical reactions

of lifeof life Mixing MediumMixing Medium

Mixture: Substance physically but not Mixture: Substance physically but not chemically combinedchemically combined• Solution: Liquid, gas, or solid uniformly Solution: Liquid, gas, or solid uniformly

distributeddistributed Solvent: What dissolves the soluteSolvent: What dissolves the solute Solute: What is to be dissolvedSolute: What is to be dissolved

Acids and Bases; Salts and BuffersAcids and Bases; Salts and Buffers

Acid:Acid: A proton donor or any substance that A proton donor or any substance that releases hydrogen ionsreleases hydrogen ions

Bases:Bases: A proton acceptor or any A proton acceptor or any substance that binds to or accepts substance that binds to or accepts hydrogen ionshydrogen ions

Salts:Salts: A cation consisting of other than a A cation consisting of other than a hydrogen ion and other than an anion or hydrogen ion and other than an anion or hydroxide ionhydroxide ion

Buffers:Buffers: A solution of a conjugate acid- A solution of a conjugate acid-base pair in which acid and base base pair in which acid and base component occur in similar concentrationscomponent occur in similar concentrations

The pH ScaleThe pH Scale Refers to the Refers to the

Hydrogen ion Hydrogen ion concentrationconcentration in a in a solutionsolution Neutral:Neutral: pH of 7 or pH of 7 or

equal hydrogen and equal hydrogen and hydroxide ionshydroxide ions

Acidic:Acidic: a greater a greater concentration of concentration of hydrogen ionshydrogen ions

Alkaline or basic:Alkaline or basic: a a greater concentration greater concentration of hydroxide ionsof hydroxide ions

EnergyEnergy

Energy:Energy: The capacity to do work The capacity to do work PotentialPotential Energy: Stored energy Energy: Stored energy KineticKinetic Energy: Does work and moves Energy: Does work and moves

mattermatter MechanicalMechanical Energy: Energy resulting from Energy: Energy resulting from

the position or movement of objectsthe position or movement of objects ChemicalChemical Energy: Form of potential energy Energy: Form of potential energy

in the chemical bonds of a substancein the chemical bonds of a substance HeatHeat Energy: Energy that flows between Energy: Energy that flows between

objects of different temperaturesobjects of different temperatures

Energy and Chemical ReactionsEnergy and Chemical Reactions

Speed of Chemical ReactionsSpeed of Chemical Reactions

Activation Energy:Activation Energy: Minimum energy reactants Minimum energy reactants must have to start a chemical reactionmust have to start a chemical reaction Catalysts:Catalysts: Substances that increase the rate of Substances that increase the rate of

chemical reactions without being permanently chemical reactions without being permanently changed or depletedchanged or depleted

Enzymes:Enzymes: Increase the rate of chemical reactions Increase the rate of chemical reactions by lowering the activation energy necessary for by lowering the activation energy necessary for reaction to beginreaction to begin

Activation Energy and EnzymesActivation Energy and Enzymes

Cells: The Fundamental Units of LifeCells: The Fundamental Units of Life

Cells are the basic Cells are the basic structural and structural and functional units of all functional units of all forms of life.forms of life. Prokaryotic cells Prokaryotic cells

(bacteria) lack a distinct (bacteria) lack a distinct nucleus.nucleus.

Eukaryotic cells (plants Eukaryotic cells (plants and animals) have a and animals) have a distinct nucleus.distinct nucleus.

Figure 2-6Figure 2-6

Animation: Prokaryotic and Eukaryotic Animation: Prokaryotic and Eukaryotic CellsCells

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Fig. 2-7, p. 38

A human body contains trillionsof cells, each with an identicalset of genes.

There is a nucleus inside eachhuman cell (except red blood cells).

Each cell nucleus has an identicalset of chromosomes, which arefound in pairs.

A specific pair of chromosomescontains one chromosome fromeach parent.

Each chromosome contains a longDNA molecule in the form of a coileddouble helix.

Genes are segments of DNA onchromosomes that contain instructionsto make proteins—the building blocksof life.

The genes in each cell are codedby sequences of nucleotides intheir DNA molecules.

Stepped Art

All Living Organisms are All Living Organisms are made up of Macromolecules:made up of Macromolecules:

Complex Carbohydrates Complex Carbohydrates ProteinsProteins Nucleic AcidsNucleic Acids LipidsLipids

Figure 2-7Figure 2-7

States of MatterStates of Matter

The atoms, ions, and molecules that make up The atoms, ions, and molecules that make up matter are found in three physical states:matter are found in three physical states: solid, liquid, gaseous.solid, liquid, gaseous.

A fourth state, plasma, is a high energy A fourth state, plasma, is a high energy mixture of positively charged ions and mixture of positively charged ions and negatively charged electrons.negatively charged electrons. The sun and stars consist mostly of plasma.The sun and stars consist mostly of plasma. Scientists have made artificial plasma (used in Scientists have made artificial plasma (used in

TV screens, gas discharge lasers, florescent TV screens, gas discharge lasers, florescent light).light).

Matter QualityMatter Quality

Matter can be classified Matter can be classified as having high or low as having high or low quality depending on quality depending on how useful it is to us as how useful it is to us as a resource.a resource. High quality matter is High quality matter is

concentrated and easily concentrated and easily extracted.extracted.

low quality matter is more low quality matter is more widely dispersed and widely dispersed and more difficult to extract.more difficult to extract.

Figure 2-8Figure 2-8

CHANGES IN MATTERCHANGES IN MATTER Matter can change from one physical form to Matter can change from one physical form to

another or change its chemical composition.another or change its chemical composition. When a physical or chemical change occurs, no When a physical or chemical change occurs, no

atoms are created or destroyed.atoms are created or destroyed.• Law of conservation of matter.Law of conservation of matter.

Physical change maintains original chemical Physical change maintains original chemical composition.composition.

Chemical change involves a chemical reaction Chemical change involves a chemical reaction which changes the arrangement of the elements which changes the arrangement of the elements or compounds involved.or compounds involved.• Chemical equations are used to represent the Chemical equations are used to represent the

reaction.reaction.

Chemical ChangeChemical Change

Energy is given off during the reaction as a product.Energy is given off during the reaction as a product.

Types of PollutantsTypes of Pollutants

Factors that determine the severity of a Factors that determine the severity of a pollutant’s effects: pollutant’s effects: chemical naturechemical nature, , concentrationconcentration, and , and persistencepersistence..

Pollutants are classified based on their Pollutants are classified based on their persistence:persistence: Degradable pollutantsDegradable pollutants Biodegradable pollutantsBiodegradable pollutants Slowly degradable pollutantsSlowly degradable pollutants Nondegradable pollutantsNondegradable pollutants

Nuclear Changes in AtomsNuclear Changes in Atoms

Natural radioactive decay: unstable isotopes Natural radioactive decay: unstable isotopes spontaneously emit fast moving chunks of spontaneously emit fast moving chunks of matter (matter (alphaalpha oror beta particlesbeta particles), high-energy ), high-energy radiation (radiation (gamma raysgamma rays), or both at a fixed ), or both at a fixed rate.rate. Radiation is commonly used in energy production Radiation is commonly used in energy production

and medical applications.and medical applications. The rate of decay is expressed as a The rate of decay is expressed as a half-lifehalf-life (the (the

time needed for one-half of the nuclei to decay to time needed for one-half of the nuclei to decay to form a different isotope).form a different isotope).

Animation: Positron-Emission Animation: Positron-Emission Tomography Tomography

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Animation: Half-Life Animation: Half-Life

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Nuclear Changes: FissionNuclear Changes: Fission

Nuclear fission: Nuclear fission: nuclei of certain nuclei of certain isotopes with large isotopes with large mass numbers are mass numbers are split apart into split apart into lighter nuclei when lighter nuclei when struck by neutrons.struck by neutrons.

Figure 2-9Figure 2-9

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235 Fig. 2-6, p. 28

Neutron

Uranium-235

Energy

Fissionfragment

Fissionfragment

n

n

n

n

n

n

Energy

Energy

Energy

Stepped Art

Nuclear Changes: FusionNuclear Changes: Fusion

Nuclear fusion: two isotopes of light elements Nuclear fusion: two isotopes of light elements are forced together at extremely high are forced together at extremely high temperatures until they fuse to form a heavier temperatures until they fuse to form a heavier nucleus.nucleus.

Figure 2-10Figure 2-10

Video: Nuclear EnergyVideo: Nuclear Energy

From ABC News, Environmental Science in the Headlines, 2005 DVD.From ABC News, Environmental Science in the Headlines, 2005 DVD.

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ENERGYENERGY

Energy is the ability to do work and transfer Energy is the ability to do work and transfer heat.heat. Kinetic energy – energy in motionKinetic energy – energy in motion

• heat, electromagnetic radiationheat, electromagnetic radiation Potential energy – stored for possible usePotential energy – stored for possible use

• batteries, glucose moleculesbatteries, glucose molecules

Electromagnetic SpectrumElectromagnetic Spectrum

Many different forms of electromagnetic Many different forms of electromagnetic radiation exist, each having a different radiation exist, each having a different wavelength and energy content.wavelength and energy content.

Figure 2-11Figure 2-11

Electromagnetic SpectrumElectromagnetic Spectrum

Organisms vary Organisms vary in their ability to in their ability to sense different sense different parts of the parts of the spectrum.spectrum.

Figure 2-12Figure 2-12

Animation: Visible LightAnimation: Visible Light

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Fig. 2-13, p. 44

Low-temperature heat (100°C or less) for space heating

Moderate-temperature heat (100–1,000°C) for industrial processes, cooking, producing

steam, electricity, and hot water

Very high-temperature heat (greater than 2,500°C) for industrial processes and producing electricity to run electrical devices (lights, motors)

Mechanical motion to move vehicles and other things) High-temperature heat (1,000–2,500°C) for industrial processes and producing electricity

Dispersed geothermal energyLow-temperature heat (100°C or lower)

Normal sunlightModerate-velocity windHigh-velocity water flowConcentrated geothermal energyModerate-temperature heat

(100–1,000°C)Wood and crop wastes

High-temperature heat (1,000–2,500°C)Hydrogen gasNatural gasGasolineCoalFood

ElectricityVery high temperature heat (greater than 2,500°C)Nuclear fission (uranium)Nuclear fusion (deuterium)Concentrated sunlightHigh-velocity wind

Source of Energy RelativeEnergy Quality

(usefulness)

Energy Tasks

ENERGY LAWS: TWO RULES WE ENERGY LAWS: TWO RULES WE CANNOT BREAKCANNOT BREAK

The first law of thermodynamics: we cannot The first law of thermodynamics: we cannot create or destroy energy.create or destroy energy. We can change energy from one form to another.We can change energy from one form to another.

The second law of thermodynamics: energy The second law of thermodynamics: energy quality always decreases.quality always decreases. When energy changes from one form to another, When energy changes from one form to another,

it is always degraded to a more dispersed form.it is always degraded to a more dispersed form. Energy efficiency is a measure of how much Energy efficiency is a measure of how much

useful work is accomplished before it changes to useful work is accomplished before it changes to its next form.its next form.

Fig. 2-14, p. 45

Chemicalenergy(food)

Solarenergy

WasteHeat

WasteHeat

WasteHeat

WasteHeat

Mechanicalenergy

(moving,thinking,

living)

Chemical energy

(photosynthesis)

SUSTAINABILITY AND MATTER SUSTAINABILITY AND MATTER AND ENERGY LAWSAND ENERGY LAWS

Unsustainable High-Throughput Economies: Unsustainable High-Throughput Economies: Working in Straight LinesWorking in Straight Lines Converts resources to goods in a manner that Converts resources to goods in a manner that

promotes waste and pollution.promotes waste and pollution.

Figure 2-15Figure 2-15

Sustainable Low-Throughput Sustainable Low-Throughput Economies: Learning from NatureEconomies: Learning from Nature

Matter-Recycling-and-Reuse Economies: Matter-Recycling-and-Reuse Economies: Working in CirclesWorking in Circles Mimics nature by recycling and reusing, thus Mimics nature by recycling and reusing, thus

reducing pollutants and waste.reducing pollutants and waste. It is not sustainable for growing populations.It is not sustainable for growing populations.

Fig. 2-16, p. 47

Recycleand

reuse

Low-quality Energy(heat)

Waste and

pollution

Pollutioncontrol

Sustainable low-waste economy

Waste and

pollution

Matter Feedback

Energy Feedback

Inputs (from environment)

Energyconservation

Matter

Energy

SystemThroughputs

Outputs(into environment)

Animation: Economic TypesAnimation: Economic Types

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