Chapter 2: Science, Matter, Energy, and Systems (Part 1) - PDF

Science, Matter, Energy and Systems CHAPTER 2 – Part 1  Objectives: At the end of this chapter, students will be able to: understand what is matter and energy establish the connections of the basic concepts of matter, energy, and systems to the emergence of environmental...

Science, Matter, Energy and Systems CHAPTER 2 – Part 1  Objectives: At the end of this chapter, students will be able to: understand what is matter and energy establish the connections of the basic concepts of matter, energy, and systems to the emergence of environmental problems identify solutions to environmental problems  0 1 What do scientists do?  Scientific Method Hypothesis Hypothesis Result Observation Ask Question Test Test Conclusion Hypothesis Hypothesis  Scientific Method Perform an Find out what Identify the Ask a question to experiment to you know about problem be investigated answer the the problem question Perform an Use hypothesis Propose a experiment to test to make testable hypothesis to Analyze the data projections projections explain the data Make Accept Revise testable hypothesi hypothesi Scientific Law projectio s s ns Scientific theory  “Scientists are curious and skeptical, and demand lots of evidence”  Four features of the scientific process: 01 Curiosity 02 Skepticis 03 04 Reproducib Peer m ility Review Good scientists But they tend to Any evidence Science is a are extremely be highly gathered must community curious about skeptical of new be reproducible effort how nature data works. Thinking critically involves 1. Be skeptical about everything we read or hear.three important steps: 2. Examine evidence and associated information, including opinions from diverse sources, and ensure their validity through validation processes. 3. Identify and evaluate our personal The results of science can “be tentative, reliable, or unreliable.”  Science has some limitations 01 02 03 cannot prove or human and not systems in the disprove anything totally free from natural world are absolutely bias complex 04 05 scientific process involves the is limited to use of understanding the statistical tools natural world “ Despite these five limitations, science is the most useful way that we have for learning about how nature works and projecting how it might behave in the future.”  0 2 What is matter?  “Matter consists of elements and compounds, which are in turn made up of atoms, ions, and molecules.” Matter Elements Compounds anything that has has a unique set of combinations of two mass and takes up properties and cannot or more different space be broken down into elements bound in simpler substances fixed proportions Atomic Theory “All elements are made of atoms”  6 protons 6 neutrons 6 electrons Model of a Carbon-12 Atom  Atoms, Molecules, and Ions are the Building Blocks of Matter Molec Atoms most basic building ules combination of two Ions an atom or group of block of matter or more atoms held atoms with one or together by more net positive chemical bond charges Ions are important for measuring a substance’s acidity Organic Compounds are Chemicals of Life Organic Inorganic Compounds “at least two carbon atoms Compounds “all other compouds with plus atoms of one or more one exception, methane elements” (CH4)” “carbon-based”  Organic Compounds hydrocarbons chlorinated simple hydrocarbons carbohydrates methane (CH4), octane (C8H18), a major insecticide DDT (C14H9Cl5) glucose (C6H12O6) component of gasoline.  Complex Organic Compounds complex carbohydrates proteins nucleic acids which consist of two or formed by monomers formed by monomers called nucleotides more monomers of called amino acids simple sugars such as glucose “DNA and RNA”  0 3 What happens when matter undergoes change?  What happens when matter undergoes change? physical chemical nuclear change change change ex: radioactive decay, ex: burning of coal to ex: melting of ice nuclear fission, and form gaseous carbon nuclear fusion dioxide “Law of Conservation of Matter” Whenever matter undergoes a physical or chemical change, no atoms are created or destroy  Connections Stuff that we put out in the trash may be buried in a sanitary landfill, but we have not really thrown it away because the atoms in this waste material will always be around in one form or another  0 4 What is energy and what happens when it undergoes change?  Energy comes in many forms forms of kinetic energy potential kinetic energy: energy stored and potentially matter in motion heat, electromagnetic available for use radiation “Law of Conservation of Energy” Whenever energy is converted to one form to another in a physical or chemical change, no energy is created or destroyed.  “Second Law of Thermodynamics” when energy is changed from one form to another, it always goes from a more useful to a less useful form  0 5 What are Systems and How Do They Respond to Change? Systems have inputs, flows, and outputs  Feedback Loop “occurs when an output of matter, energy, and information is fed back into the system as an input and leads to changes in that system” positive feedback loop causes a system to change further in the same direction negative feedback loop causes a system to change in the opposite direction from which is it moving negative feedback loop causes a system to change in the opposite direction from which is it moving  Reinforcing (positive) Feedback Loops Neutron collides with In nuclear fission, a neutron atom (amplifier) collides with an atom causing its nucleus to split apart and Atom splits release 2-3 neutrons. These Nuclear +1 x +1= +1 apart Fission neutrons go on to collide with other atoms, which then release Releases more more neutrons. This cycle neutrons continues, growing as increasingly more atoms are split.  Balancing (Negative) Feedback Loops Exercise on a hot day Your internal body temperature needs to stay constant. When you (amplifier exercise or go outside on a hot day, your temperature starts to increase. Your nervous system sends information to your brain about the High Normal Body +1 x -1= +1 change in temperature, and you Temperature Temperature brain in turn sends signals to your skin to tell you to sweat. The evaporation of the sweat helps keep your body cooler. When you quit Sweating & exercising or go back indoors, your Quitting body cools back down to your Exercise normal temperature. Signals are again sent to your brain, and your (stabilizer) brain tells your skin to quit sweating.  time delay lack of response during a period of time between the input of a feedback stimulus and the system’s response to it tipping point the point at which a fundamental shift in the behavior of a system occurs  Three big ideas: 1.There is no away (Law of Conservation of Matter) 2.You cannot get something for nothing (Law of Conservation of Energy) 3.You cannot break even (Second Law of Thermodynamics) Thank you!