Transcript Science, Systems, Matter, & Energy Chapter 2 Chapter Overview Questions What are major components and behaviors of complex systems?  What are the basic.

Science, Systems, Matter, & Energy
Chapter 2
Chapter Overview Questions
What are major components and
behaviors of complex systems?
 What are the basic forms of matter, and
what makes matter useful as a resource?
 What types of changes can matter
undergo and what scientific law governs
matter?

Chapter Overview Questions
(cont’d)

What are the major forms of energy, and what
makes energy useful as a resource?
 What are two scientific laws governing
changes of energy from one form to another?
 How are the scientific laws governing
changes of matter and energy from one form
to another related to resource use,
environmental degradation and
sustainability?
The Effects of Deforestation on
the Loss of Water and Soil
Nutrients
Science and Technology
2.1
Science – knowledge of how the world
works
 Technology – creation of new
processes intended to improve the
quality of life

Scientific Method
Ask a question
Do experiments
and collect data
Interpret data
Formulate
hypothesis
to explain data
Well-tested and
accepted patterns
In data become
scientific laws
Do more
Experiments to
test hypothesis
Revise hypothesis
if necessary
Well-tested and
accepted
hypotheses
become
scientific theories
Core Case Study:
Environmental Lesson from Easter
Island

Thriving society
– 15,000 people by 1400.

Used resources faster
than could be renewed
– By 1600 only a few
trees remained.

Civilization collapsed
– By 1722 only several
hundred people left.
Figure 2-1
Scientists Use Reasoning, Imagination, and
Creativity to Learn How Nature Works

Important scientific tools
– Inductive reasoning: Specific observations and
measurements to arrive to a general conclusion.
– Deductive reasoning: uses logic to arrive to a
specific conclusion based on generalization.

Scientists also use
– Intuition
– Imagination
– Creativity
Scientific Theories and Laws Are the
Most Important Results of Science

Scientific theory
– Widely tested
– Supported by extensive evidence
– Accepted by most scientists in a particular
area

Paradigm Shift
When new information of ideas can disprove
or overthrow a well-accepted scientific theory
– An example is plate tectonic theory
Environmental Science Has Some Limitations

Scientist can disprove things, but not prove
anything absolute

Bias can be minimized by scientists

Environmental scientist often rely on estimates

Environmental phenomena involve interacting
variables and complex interactions
Matter
2.2
Nature’s Building Blocks; anything that
has mass and takes up space
 Types of Matter:

– elements – single type of atoms, cannot
be broken down into other substances
• 92 natural +18 synthesized
– compounds - 2 or more different
elements, held together by chemical bonds
(fixed proportions) ex: H2O
Elements Important to the Study of
Environmental Science
8 elements make up 98.5% of the
Earth’s crust
Compounds Important to the
Study of Environmental Science
Building Blocks

Atoms- smallest unit of matter
– Atomic theory- all elements made up of
atoms
 Molecules- Two or more atoms of the
same or different elements held together
by chemical bonds

ex: H2, O2, N2
Basic Chemistry Terms

Atomic Number - # of protons

Subatomic particles
– Protons (p) with positive charge and
neutrons (0) with no charge in nucleus
– Negatively charged electrons (e) orbit the
nucleus
 Mass
Number- protons (+) plus
neutrons(0)
Atoms, Ions, and Molecules Are the
Building Blocks of Matter (2)

Ions- electrically
charged atom or
combination of
atoms
– Metals- LOSE e– Nonmetals- gain e-

pH
–
–
–
–
–
Measure of acidity
H+ and OHNeutral -7
Basic 8-14
Acid 1-6
Ions Important to the Study of
Environmental Science
Loss of NO3− from a Deforested
Watershed
Isotopes

Elements with
same atomic
number but a
different mass #
(C12, C13 & C14)
Atoms, Ions, and Molecules Are the
Building Blocks of Matter (3)
Chemical formula – type of short hand to
show the type and # of atoms/ions in a
compound. Ex. NaCl or CH4
Ionic compound- made up of opposite
charged ions Na+ ClCovalent compounds- uncharged atoms
CH4
Organic Compounds

Contain carbon and hydrogen
– Hydrocarbons C8H18 gasoline and chlorinated
hydrocarbons C14H9Cl5 DDT
– Simple carbohydrates C6H12O6
– Macromolecules: complex organic
molecules
•
•
•
•
Complex carbohydrates
Proteins
Nucleic acids
Lipids
Inorganic Compounds

No carbon to carbon or carbon to
hydrogen bonding, not originating from
a living source
– Earth’s crust – minerals,water
– Water, nitrous oxide, nitric oxide, carbon
monoxide, carbon dioxide, sodium
chloride, ammonia
Matter Comes to Life through Genes,
Chromosomes, and Cells
Cells:
fundamental
units of life
 Genes:
sequences of
nucleotides
within the DNA
 Chromosome:
composed of
many genes

Matter Occurs in Various
Physical Forms

Solid

Liquid

Gas

High-quality matter

Low-quality matter
Matter Quality: High or Low

A measure of how useful matter is for
humans based on availability and
concentration.
Matter Undergoes Physical, Chemical, and
Nuclear Changes

Physical change-
chemical
composition not changed ex:
water and ice

Chemical change or
chemical reaction- chemical
composition has changed

Nuclear change
– Natural radioactive decay
• Radioisotopes: unstable
– Nuclear fission (split apart)
– Nuclear fusion (fuse together)
Nuclear Changes

Nuclei of certain isotopes spontaneously
change (radioisotopes) or made to change
into one or more different isotopes
–
–
–
–
–
Alpha particles
Beta particles
Gamma rays
Neutrons
Positrons
Radioactive decay
Alpha particle
(helium-4 nucleus)
Radioactive
isotope
Gamma rays
Beta particle (electron)
Uranium-235
Nuclear fission
Fission
fragment
Energy
n
n
Neutron
Energy
n
Nuclear fusion
n
Energy
n
Uranium-235
Reaction
conditions
Fuel
Proton
Neutron
Hydrogen-2
(deuterium nucleus)
100
million °C
Hydrogen-3
(tritium nucleus)
n
Products
Helium-4 nucleus
Fission
Energy
fragment
Energy
Stepped Art
Neutron
Fig. 2-7, p. 41
Ionizing and Nonionizing Radiation

Ionizing: radiation with
enough energy to
change the structure of
molecules or atoms
– Gamma, ultraviolet

Nonionizing: radiation
that does not change the
structure of molecules or
atoms
– Alpha, infrared
Half - Life
Time needed for one-half of the nuclei
in a radioisotope to decay and emit
their radiation.
 General rule for decay: goes through
10 half –lives before it becomes a nonradioactive form.

We Cannot Create or Destroy Matter

Law of conservation of
matter
– no atoms are created/destroyed
during a physical or chemical
change.

Matter consumption
– Matter is converted from one
form to another
Energy quality

2.4
Measure of how useful an energy source is in
terms of concentration and ability to perform
useful work
Severity of Pollutants
Chemical Nature
 Concentration: ppm
 Persistence: categories

– Degradable/Biodegradable: human
sewage, leaves
– Persistent -decades-plastics and DDT
– Nondegradable-lead, arsenic, mercury
Energy
E= capacity to do work (w =f x d)
 Types:

– Kinetic Energy -energy in motion
– Potential energy - stored energy

Forms of energy:
– Light, heat, electrical, chemical,
electromagnetic radiation
Electromagnetic radiation
* energy that travels in waves
* shorter wave lengths = high energy
X-ray image of Sun
UV image of Sun
Radio image of sun
Light image of Sun
10
5
0
Visible
Ultraviolet
Energy emitted from sun (kcal/cm2/min)
15
0.25
Infrared
1
2
Wavelength (micrometers)
2.5
3
Fig. 2-8, p. 42
US Frequency Allocations
First Law of Thermodynamics

Also known as law of conservation of energy
 Energy can change from one form to another
but can never be destroyed
 No “away” in “throw away”
-things that have been thrown away are still
present on Earth, but just exist in another
form.
Second Law of Thermodynamics

You cannot even break even
– When energy is changed from one form to
another, some of the useful energy is
always degraded to lower quality, more
dispersed, less useful energy.
The Second Law of
Thermodynamics
in Living Systems
Systems
2.5
– Systems: set of components that function and
interact in some way.
•
Key Components:
– Inputs from the environment (energy, matter, information)
– Throughputs: flow of input within the system
– Outputs to the environment (energy, matter, information)
•
Models can used to test these systems.
– Ex: Mathematical Models – use of equations
Feedback Loop and Systems
 Change
in one part of a system
influences another part of the
system
Positive Feedback Loop
– Causes system to change in same direction.
• Example: Exponential growth of population – more individuals
lead to increased number of births
Negative Feedback Loop
– Causes system to change in opposite direction.
• Example: Temperature regulation in humans – increased
temperature leads to decrease in temperature by sweating
What Affects Complex Systems?

Time lags/ time delays – change in a system
leads to other changes after a delay

(input
response)
– Problems can build slowly in systems until reaching a tipping point
– Ex: lung cancer

Resistance to change – built in resistance –
political or economic

Synergy-when two or more processes interact so
that the combined effect is greater

Chaos – unpredictable behavior in a system
Implications for the Environment –
High Waste Society
Implications for the
Environment – Low Waste Society