1. Environmental Systems Chapter 2

2. Matter “anything that occupies space and has mass” Atoms Molecules Periodic Table Atomic Number http://science.howstuffworks.com/laser1.htm

3. No atoms are ever destroyed or created, but the bonds may change between them a. law of conservation of matter - “ matter cannot be created or destroyed; it can only change form”

4. Radioactivity Unstable isotopes are radioactive Radioactive decay a. spontaneous release of material from nucleus ex) Uranium-235 ( 235 U) Half-life a. measurement of radioactive decay

5. Chemical Bonds Covalent Bonds (sharing of e-) a. CH 4 (methane) Ionic Bonds (transfer of e-) a. NaCl (salt) Hydrogen Bonds (unequal sharing of e-) a. weak b. H 2 O

6. Properties of Water Surface tension Capillary action Boiling and freezing point Acts as a solvent http://environment.nationalgeographic.com/environment/photos/freshwater-insects/

7. pH Acid a. dissociates into positively charged H+ and negatively charged ions b. HNO 3 and H 2 SO 4 Base a. dissociates into negatively charged OH- ions and positively charged ions b. NaOH http://sanibelseaschool.org/classroom/ph

8. Organic Molecules Organic v. Inorganic Compounds Examples of Organic Compounds a. Carbohydrates b. Lipids c. Proteins d. Nucleic Acids

9. Energy “ability to do work, or transfer heat” Majority on Earth derives from the Sun

10. Forms of Energy Joule: basic unit of energy (J) Energy and Power a. energy-ability to do work power-rate at which work is done therefore, energy = power X time power = energy / time

11. Kinetic and Potential Energy a. Potential-stored energy not yet released ex) water behind a dam b. Kinetic-energy of motion ex) electricity created from water captured by dam

12. Energy Laws 1 st Law of Thermodynamics a. “energy is neither created nor destroyed” 2 nd Law of Thermodynamics a. “when energy is transformed, the quantity of energy remains the same but its ability to do work diminishes”

13. Systems Open System a. exchange of matter or energy across system boundaries ex) ocean Closed System a. matter and energy exchange across the boundaries does not happen ex) underground cave system

14. Input a. additions to a system Output a. losses from the system

15. Steady State “inputs equal outputs so that the system is not changing over time” Allows us to know if the amount of a resource or pollutant is increasing, decreasing or staying the same

16. Feedbacks Positive Feedback Loop a. amplifies change b. births in regards to human population Negative Feedback Loop a. responds to a change by returning to its original state to reach homeostasis b. thermostat