es chapter2

7/30/2019 ES Chapter2

1/77

ENVIRONMENTALSCIENCE 13e

CHAPTER 2:Science, Matter, and Energy


2/77

Core Case Study:

A Story about a Forest (1)

Hubbard Brook Experimental Forest

Question: What is the environmental

impact of forest clear-cutting? Controlled experiment isolate

variables

Control group

Experimental group


3/77

Core Case Study:

A Story about a Forest (2)

Measure loss of water and nutrients

Compare results

3040% increase in runoff68 times more nutrient loss

Draw conclusions

Cause-and-effect relationships


4/77

Fig. 2-1, p. 23


5/77

Fig. 2-3, p. 30


6/77

Undisturbed(control)watershed

Disturbed(experimental)watershed

Year

Nitrate(NO3

)concentratio

n

(milligram

sperliter)

Fig. 2-3, p. 30

60

40

20

1963 1964 1965 1966 1967 1968 1969 1970 1970 1972


7/77

2-1 What Do Scientists Do?

Concept 2-1 Scientists collect dataand develop theories, models, and

laws about how nature works.


8/77

Science

Search for order in nature

Observe behavior

Attempt to identify cause and effectMake predictions

Test predictions

Draw conclusions


9/77

The Scientific Process (1)

Identify problem/question

Learn what is known about

problem/question Ask question to be investigated

Collect data

Formulate a testable scientifichypothesis


10/77


Make testable projections

Test projections with experiments

Develop models

Propose scientific theories

Derive naturallaws


11/77


Four features of the scientific

process:

Curiosity

Skepticism

Peer review

Reproducibility


12/77Fig. 2-2, p. 25


13/77Fig. 2-2, p. 25

Scientific lawWell-accepted

pattern in data

Identify a problem

Find out what is known

about the problem(literature search)

Ask a question to be

investigated

Perform an experimentto answer the question

and collect data

Analyze data(check for patterns)

P


14/77

Make testablepredictions

Propose anhypothesis

to explain data

Use hypothesis to

make testablepredictions

Perform anexperiment

to test predictions

Accepthypothesis

Scientific theoryWell-tested andwidely accepted

hypothesis

Revisehypothesis

Testpredictions

Fig. 2-2, p. 25


15/77

Scientific theory

Well-tested andwidely acceptedhypothesis

Stepped Art

Testpredictions

Make testablepredictions

Accepthypothesis

Revisehypothesis

Perform an experiment

to test predictions

Use hypothesis to make testablepredictions

Propose an hypothesisto explain data

Analyze data(check for patterns)

Scientific lawWell-acceptedpattern in data

Perform an experimentto answer the question

and collect data

Ask a question to be

investigated

Find out what is knownabout the problem(literature search)

Identify a problem

Fig. 2-2, p. 25


16/77

Results of Science

Goals

Scientific theories

Scientific laws

Degree of certainty and general

acceptance

Frontier/tentative science

Reliable science

Unreliable science


17/77

Scientific Limitations

Limitations 100% certain?

Absolute proof versus probability

Observational biasComplex interactions, many variables

Estimates and extrapolating numbers

Mathematical models


18/77

Science Focus: Climate Change

(1) Natural greenhouse effect

Keeps atmosphere temperatures moderate

Three questions

1. How much warming over the last 50years?

2. How much of the warming is caused by

humans adding carbon dioxide toatmosphere?

3. How much will the atmosphere warm in

the future, and what effects will it have?


19/77

Science Focus: Climate Change

(2) International Panel on Climate Change

2007 IPCC report:

Very likely: 0.74 C increase 1906-2005

Very likely: human activities main cause ofglobal warming

Likely: earth mean surface temperature toincrease by ~3 C between 2005 and 2100.

Climate change critics: most are notclimate experts


20/77

2-2 What Is Matter and How Do Physicaland Chemical Changes Affect It?

Concept 2-2A Matter consists ofelements and compounds, which are inturn made up of atoms, ions, or molecules.

Concept 2-2B Whenever matterundergoes a physical or chemical change,no atoms are created or destroyed (thelaw of conservation of matter).


21/77

What Is Matter?

Matter has mass and occupiesspace

Elements and CompoundsAtoms

Ions

Molecules


22/77

Table 2-1, p. 29


23/77

Building Blocks of Matter (1)

Atomic Theory elements made fromatoms

Atoms

Protons positive charge

Neutrons uncharged

Electrons negative charge

Nucleus

One or more protons

Usually one or more neutrons


24/77

Supplement 6, Fig. 1, p. S26


25/77


6 protons

6 neutrons

6 electrons


26/77


Atomic number

Number of protons

Massnumber Neutrons + protons

Isotopes

Same atomic number, different mass

Same number of protons, different number of

neutrons


27/77


Ion

One or more net positive or negative electrical

charges

Molecule Combination of two or more atoms

Chemical formula

Number and type of each atom or ion

Compounds

Organic

Inorganic


28/77



29/77


Hydrochloricacid (HCl)

Gastric fluid(1.03.0)

Lemon juice,some acid rain

Vinegar, wine,

beer, oranges

Tomatoes

BananasBlack coffee

BreadTypical rainwater

Urine (5.07.0)

Milk (6.6)

Pure waterBlood (7.37.5)

Egg white (8.0)

Seawater (7.88.3)Baking soda

100

101

102

103

104

105

106

107

108

109

1010

1011

1012

1013

1014Sodium hydroxide (NaOH)

Phosphate detergentsBleach, Tums

Soapy solutions,Milk of magnesia

Household ammonia(10.511.9)

Hair remover

Oven cleaner


30/77



31/77


CI2chlorine

H2hydrogen

O2oxygen

N2nitrogen

H2O

water

NO

nitric oxide

CO

carbon monoxide

HCI

hydrogen chloride

NO2

nitrogen dioxide

O3

ozone

SO2

sulfur dioxide

CO2

carbon dioxide

H2S

hydrogen sulfide

CH4

methane

NH3

ammonia

SO3

sulfur trioxide


32/77

Table 2-2, p. 29


33/77

Table 2-3, p. 30


34/77

Organic Compounds

Carbon-based compounds

Hydrocarbons

Chlorinated hydrocarbons

Simple carbohydrates

Complex carbohydrates

Proteins

Nucleic acids (DNA and RNA)

Lipids


35/77

Matter Becomes Life

Cells

Genes

DNATraits

Chromosomes

DNA

Proteins


36/77

Fig. 2-4, p. 31

A human body contains trillions


37/77

A human body contains trillionsof cells, each with an identical setof genes.

Genes are segments of DNA onchromosomes that contain instructionsto make proteinsthe building blocks

of life.

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

A specific pair of chromosomescontains one chromosome from eachparent.

Each cell nucleus has an identical setof chromosomes, which are found in

pairs.

Each human cell (except for redblood cells) contains a nucleus.

Fig. 2-4, p. 31

A human body contains trillions


38/77

A human body contains trillionsof cells, each with an identical setof genes.

Genes are segments of DNA onchromosomes that contain instructionsto make proteinsthe building blocks

of life.

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

A specific pair of chromosomescontains one chromosome from eachparent.

Each cell nucleus has an identical setof chromosomes, which are found in

pairs.

Each human cell (except for redblood cells) contains a nucleus.

Stepped ArtFig. 2-4, p. 31


39/77

Matter Quality

Usefulness as a resource

Availability

Concentration

High quality

Low quality


40/77

Fig. 2-5, p. 32

Low QualityHigh Quality


41/77

Aluminum ore

Solid

Salt

Coal

Gasoline

Aluminum can

Gas

Solution of salt in water

Coal-fired powerplant emissions

Automobile emissions

Fig. 2-5, p. 32


42/77

Changes in Matter

Physical

Chemical

Law of Conservation of MatterMatter only changes from one form to

another


43/77

p. 32


44/77

p. 32

Reactant(s) Product(s)

Carbon + Oxygen

C + O2

Black solid Colorless gasColorless gas

Energy

Energy

Energy

Carbon dioxide +

CO2 +

+C CO O

O

O

+


45/77

Nuclear Changes (1)

Radioactive decay unstableisotopes

Alpha particles

Beta particles

Gamma rays


46/77

Nuclear Changes (2)

Nuclear fission

Large mass isotopes split apart

Chain reaction

Nuclear fusion

Two light isotopes forced together

High temperature to start reaction

Stars


47/77

Fig. 2-6, p. 33


48/77

Radioactive decay

Radioactive isotope

Gamma rays

Beta particle(electron)

Alpha particle(helium-4 nucleus)

Radioactive decayoccurs when nuclei ofunstable isotopesspontaneously emit fast-moving chunks of matter(alpha particles or beta

particles), high-energyradiation (gamma rays), orboth at a fixed rate. Aparticular radioactiveisotope may emit any oneor a combination of thethree items shown in thediagram.

Fig. 2-6, p. 33

++


49/77

Nuclear fission Uranium-235

Uranium-235

Neutron

Fissionfragment

Fissionfragment

Energy

Energy

Energy

Energy

Nuclear fission occurs when thenuclei of certain isotopes with largemass numbers (such as uranium-235)are split apart into lighter nuclei when

struck by a neutron and releaseenergy plus two or three moreneutrons. Each neutron can trigger anadditional fission reaction and lead toa chain reaction, which releases anenormous amount of energy.

Fig. 2-6, p. 33

n

n

nn

n

n


50/77

Nuclear fusion

Fuel

Proton Neutron

Hydrogen-2(deuterium nucleus)

Hydrogen-3(tritium nucleus)

100million C

Reactionconditions Products

Helium-4 nucleus

Energy

Neutron

Nuclear fusion occurs when twoisotopes of light elements, such

as hydrogen, are forced togetherat extremely high temperaturesuntil they fuse to form a heaviernucleus and release a tremendousamount of energy.

Fig. 2-6, p. 33

Uranium-235


51/77

Neutron

Uranium-235

Fission

fragment

Fission

fragment

Energyn

n

n

Energy

Energy

n

n

n

Energy

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Stepped Art

Fig. 2-6, p. 33


52/77

2-3 What Is Energy and How Do Physicaland Chemical Changes Affect It?

Concept 2-3A When energy is converted fromone form to another in a physical or chemicalchange, no energy is created or destroyed (first

law of thermodynamics).

Concept 2-3B Whenever energy is convertedfrom one form to another in a physical orchemical change, we end up with lower qualityor less usable energy than we started with(second law of thermodynamics).


53/77

What Is Energy?

Energy the capacity to do work ortransfer heat


54/77

Types of Energy

Potentialenergy stored energyGasoline

Water behind a dam

Kineticenergy energy in motionWind, flowing water, electricity

Heat

flow from warm to coldElectromagnetic radiation

wavelength and relative energy


55/77

Fig. 2-7, p. 34


56/77

Fig. 2-7, p. 34

Ultraviolet

Ene

rgyemittedfro

ms

un(kcal/cm

2/min)

0

5

10

15

1 2 2.50.25 3

Wavelength (micrometers)

Visible

Infrared


57/77

Energy Quality (1)

High-quality energy

Concentrated, high capacity to do work

High-temperature heat

Nuclear fission

Concentrated sunlight

High-velocity windFossil fuels


58/77

Energy Quality (2)

Low-quality energy

Dispersed

Heat in atmosphere

Heat in ocean


59/77

Laws of Thermodynamics

First law of thermodynamics

Energy input = Energy output

Energy is neither created or destroyed

Energy only changes from one form to

another

Second law of thermodynamicsEnergy use results in lower-quality

energy

Dispersed heat loss

Consequences of the Second


60/77

Consequences of the Second

Law of Thermodynamics

Automobiles

~13% moves car

~87% dissipates as low-quality heat into the

environment

Incandescent light bulb

~5% useful light

~95% heat


61/77

Fig. 2-8, p. 36


62/77

Solarenergy

Chemical energy(photo-synthesis)

Mechanicalenergy

(moving,thinking, living)

Chemicalenergy(food)

Wasteheat

Wasteheat

Wasteheat

Wasteheat

Fig. 2-8, p. 36


63/77

Three Big Ideas of This Chapter

There is no away

Law of conservation of matter

You cannot get something for nothingFirst law of thermodynamics

You cannot break even

Second law of thermodynamics

A i ti S b t i ti l


64/77

Animation: Subatomic particles

Animation: Atomic number, mass
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/atomic_particles.html


65/77

at o to c u be , assnumber

A i ti I i b d
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/mass_number.html


66/77

Animation: Ionic bonds

A i ti C b b d
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/ionic_bond.html


67/77

Animation: Carbon bonds

Animation Half life
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/carbon_bonding.html


68/77

Animation: Half-life

Animation: Visible light
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/half_life.html


69/77

Animation: Visible light

Animation: Total energy remains
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/light_wavelength.html


70/77

gyconstant

Animation: Energy flow
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/energy_constant.html


71/77

Animation: Energy flow

Animation: Economic types
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/energy_flow.html


72/77

Animation: Economic types

Animation: Martian doing
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/hi_low-throughput.html


73/77

gmechanical work

Animation: Energy flow from Sun
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/martian_working.html


74/77

Animation: Energy flow from Sun

to Earth
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/sun_to_earth.html


75/77

Animation: Energy Use

Animation: Hubbard Brook
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/energy_pie.html


76/77

Animation: Hubbard Brook

Experiment

Animation: Categories of Food
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/hubbard_brook.html


77/77

Animation: Categories of Food

Webs
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/food_webs_v2.html

es chapter2

Documents