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

2. Science is an endeavor to discover how nature works
Science is an endeavor to discover how nature works. It has limitations and hypothesis are tentative and testable statements that must be capable of being supported or not supported by observational evidence.
Data – information required to answer the scientists questions
Model – an approximate representation or simulation of a system being studied.
Scientific Theory – a well-tested and widely accepted scientific hypothesis or a group of related hypothesis

3. Scientific Law – a well tested and widely accepted description of what we find happening over and over again, the exact same way in nature. Peer Review – scientists sharing information with other scientists working in the same field. Inductive Reasoning – using specific observations and measurements to arrive at a general conclusion or hypothesis. Deductive Reasoning – using logic to arrive at a specific conclusion based on generalization or premise.

4. Paradigm Shift – when the majority of scientists in a field accept new ideas and discoveries and build a new framework for laws and theories, overthrowing older laws and theories. Tentative Science/Frontier Science – hypotheses that have not been widely tested or studied and have not been accepted by peer review; tend to capture news and headlines. Reliable Science – consists of data, hypotheses, theories, and laws that are widely accepted Unreliable Science -

5. Essentially 100% of the energy that fuels the earth comes from the sun
EARTH’S ENERGY BALANCE

6. Solar Energy Enters Ecosystems via Photosynthesis
Terrestrial Ecosystems
Aquatic Ecosystems
PHYTOPLANKTON

7. Elements important to the Study of Environmental Science
Hydrogen Bromine Carbon Sodium Oxygen Calcium Nitrogen Lead Phosphorus Mercury Sulfur Arsenic Chlorine Uranium Flourine

8. Ions Important to the Study of Environmental Science
Hydrogen - H+ Sodium – Na+ Calcium – Ca2+ Aluminum – Al3+ Ammonium – NH4+ Chlorine – Cl- Hydroxide – OH- Nitrate – NO3- Sulfate – SO42- Phosphate – PO43-

9. Compounds Important to the Study of Environmental Science
Sodium Chloride – NaCl Carbon Monoxide – CO Carbon Dioxide – CO2 Nitric Oxide – NO Nitrogen Dioxide – NO2 Nitrous Oxide – N2O Nitric Acid – HNO3

10. Compounds Important to the Study of Environmental Science Cont.
Methane – CH4
Glucose – C6H12O6
Water – H2O
Hydrogen Sulfide –H2S
Sulfur Dioxide – SO2
Sulfuric Acid – H2SO4
Ammonia – NH3

11. Law of Conservation of Matter
When a chemical or physical change occurs, no atoms are created or destroyed. DUH.

12. Law of conservation of Energy (also known as the 1st law of thermodynamics)
When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed. Once again, DUH. Energy Input always = Energy Output

13. 2nd Law of Thermodynamics
When energy changes from one form to another, we always end up with lower-quality or less usable energy than we started with. Energy always goes from a more useful to a less useful form when it is changed from one form to another.

14. What are Systems and how do they respond to change?
System – a set of components that function and interact in some regular way. Most systems have the following key components: Inputs from the environment Flows or throughputs of matter and energy within the system at certain rates Outputs to the environment

15. Feedback Loops
Feedback – any process that increases or decreases a change to a system. Feedback Loop – when an output of matter, energy, or information is feed back into the system as an input and leads to changes in that system. Positive Feedback Loop – system changes further in the same direction. (Decreasing Vegetaion in a valley) Negative Feedback Loop – system changes in the opposite direction. (Your thermostat at home)

16. Negative/Positive Feedbacks