1. Science. Matter. Energy. Systems.
Chapter 2 1

2. Important Definitions to Review
Science – knowledge of how the world works
Technology – creation of new processes intended to improve the quality of life
Law – certain phenomena always act in a predictable manner
Theory – rational explanation for numerous observations of a certain phenomena – global warming due to greenhouse effect
Accuracy – measurement agrees with the accepted correct value
Precision – measure of reproducibility
Inductive reasoning- using observations and facts to arrive at generalizations
Deductive reasoning - using logic to arrive at a specific conclusion 2

3. Scientific method identify question/problem
HYPOTHESIS – proposed to explain observed patterns
Complete experiment and collect data
Analysis and conclusions (results tentative, reliable or unreliable)
Experiments subject to peer review
identify biases
Identify limitations 3

4. Systems system: set of components that interact in some regular way
Open system: systems the exchange both energy and matter across their boundaries
most environmental systems open
Inputs - matter, energy, information
Throughput - flow of input
Output - matter, energy, information flowing out
Closed system: exchange energy but not matter across their boundaries
ex. water cycle
feedback loop: Change in one part of a system influences another part of the system 4

5. 5

6. Positive feedback loop
causes a system to change further in the same direction. (farther from normal)
Exponential growth of population – more individuals lead to increased number of births
Precipitation causes erosion. Erosion causes plants to die. More precipitation causes more erosion and more vegetation death. 6

7. Negative feedback loop
system to change in the opposite direction from which it is moving (closer to normal)
Temperature regulation in humans – increased temperature leads to decrease in temperature by sweating 7

8. Implications for the environment – High waste society8

9. Implications for the environment – Low waste society9

10. Complex systems Chaos – unpredictable behavior in a system
Time lags – change in a system leads to other changes after a delay
lung cancer
Resistance to change – built in resistance –
political, economic
Synergy-when two or more processes interact so that the combined effect is greater
Can be beneficial or harmful
Chaos – unpredictable behavior in a system 10

11. Matter and Energy Resources
Nature’s Building Blocks
anything that has mass and takes up space 11

12. Forms of matter elements – single type of atoms 110 elements
92 natural, 18 synthesized
table 2.1 (important elements)
compounds - 2 or more elements, held together by chemical bonds
table 2.3 (important compounds) 12

13. Atomic Theory Definitions
atoms - smallest units of matter- protons (+), neutrons (0), electrons (-)
protons/neutrons in nucleus of atom
atomic # = # of protons
isotope: same atomic number but different mass number (different form of the same element)
Carbon-14; Uranium-235
ion - electrically charged atoms
Table 2.2 (important ions)
molecules - combinations of atoms of the same or different elements 13

14. Some Important elements
Some Important elements composition by weight – only 8 elements make up 98.5% of the Earth’s crust 14

15. Organic Compounds with 2 or more atoms of carbon
hydrocarbons: carbon and hydrogen atoms
methane CH4 (only exception to 2 C rule)
Octane C8H18
chlorinated hydrocarbons: carbon, hydrogen and chlorine
DDT C14H9Cl5
Simple carbohydrates: carbon, hydrogen and oxygen
glucose C6H12O6
Also includes Polymers.
complex carbohydrates (made of simple sugars), nucleic acids (made of nucleotides), proteins (made of amino acids) and lipids 15

16. Inorganic compounds no carbon, not originating from a living source
Earth’s crust – minerals, water
water, nitrous oxide, nitric oxide, sodium chloride, ammonia 16

17. Matter quality
Measure of how useful a matter is for humans based on availability and concentration 17

18. Energy capacity to do work and transfer heat
Kinetic Energy -energy in action
electromagnetic radiation (energy in waves resulting from electrical/magnetic fields), heat (energy in moving atoms)
Potential energy - stored energy that is potentially available; may be changed to kinetic 18

19. Electromagnetic radiation
different wave lengths
Shorter wavelength= high energy
disrupts cells with long term exposure 19

20. Energy sources
99% of the energy that supports earth comes from the sun
without it earth’s temperature -240 C or -400 F
allows for wind, hydro and biomass sources of renewable energy
1% - commercial sources. Burning oil, coal and natural gas. 20

21. Energy quality
Measure of how useful an energy source is in terms of concentration and ability to perform useful work 21

22. Energy Changes energy changes governed by 2 scientific laws
law of conservation of energy (first law of thermodynamics)
no energy is created or destroyed as it changes from one form to another
energy input = energy output
can lose energy quality (converted to a less useful form)
second law of thermodynamics
as energy changes form we end up with a lower quality or less usable energy source (heat) 22

23. Nuclear Changes
nuclei of certain isotopes spontaneously change (radioisotopes) or made to change into one or more different isotopes
Occurs with one of the following particles:
Alpha particles – fast moving (2 protons+2 neutrons)
Beta particles – high speed electrons
Gamma particles - high energy electromagnetic radiation
radioactive decay, nuclear fission, nuclear fusion 23

24. Use….radioisotopes Estimate age of rocks and fossils
Tracers in pollution detection and medicine
Genetic control of insects 24

25. Half – Life (radioactive decay)
time needed for one-half of the nuclei in a radioisotope to decay and emit their radiation.
ranges from fraction of a second to millions of years 25

26. Nuclear Fission
certain isotopes (uranium-235) split apart into lighter nuclei + neutrons when struck by neutrons
chain reaction releases energy
Releases an enormous amount of energy very quickly 26

27. Nuclear fusion
two isotopes (hydrogen) forced together at extremely high temperatures (100 million C)
Fuse to form a heavy nucleus and release a tremendous amount of energy 27