Science, Matter, and Energy Chapter 2

An Environmental Lesson from Easter Island- Tragedy of the Commons Colonized about 2,900 years ago Colonized about 2,900 years ago Soil and tree resources exhausted Soil and tree resources exhausted Over 300 statues Over 300 statues By 1600 AD, few trees left By 1600 AD, few trees left Islanders trapped and starved Islanders trapped and starved War / cannibalism over remaining resources War / cannibalism over remaining resources Dutch arrived 1722 Dutch arrived 1722

Key Concepts Science is a process for understanding Science is a process for understanding Matter: Basic forms and resources Matter: Basic forms and resources Energy: Basic forms and resources Energy: Basic forms and resources Scientific laws governing matter and energy Scientific laws governing matter and energy Physical and chemical properties Physical and chemical properties Nuclear changes and radioactivity Nuclear changes and radioactivity

Science and Critical Thinking What is science?- attempt to discover order in nature & make predictions What is science?- attempt to discover order in nature & make predictions Scientific data Scientific data Experiments Experiments Scientific hypotheses- working explanation for observations Scientific hypotheses- working explanation for observations Scientific models Scientific models Scientific theories- repeatedly supported hypothesis- reliable & accepted Scientific theories- repeatedly supported hypothesis- reliable & accepted Natural laws- well-tested and accepted patterns in data Natural laws- well-tested and accepted patterns in data

Scientific Process

Science vs. Junk Science Scientific method(s) - single and multivariable analysis Scientific method(s) - single and multivariable analysis Scientific results- “ absolute truth?” Scientific results- “ absolute truth?” Frontier science- not confirmed Frontier science- not confirmed Sound science (consensus science) - widely accepted, peer review Sound science (consensus science) - widely accepted, peer review Junk science - Untested ideas presented as sound science- can be used to mislead for political gain Junk science - Untested ideas presented as sound science- can be used to mislead for political gain

Matter and its Types What is matter? = anything with mass. 2 forms: 1. Elements = building blocks of matter 2. Compounds = 2 or more elements bonded chemically What is matter? = anything with mass. 2 forms: 1. Elements = building blocks of matter 2. Compounds = 2 or more elements bonded chemically Chemical bonds Chemical bonds Atoms = smallest unit of matter Atoms = smallest unit of matter Ions = electrically charged atom Ions = electrically charged atom Chemical formulas Chemical formulas Organic vs. inorganic compounds Organic vs. inorganic compounds

Fig. 2-3, p.23 Levels of Organization of Matter

Organic Compounds- contain at least 2 or more C atoms combined with each other & atoms of 1 or more other elements. Hydrocarbons: ex. CH 4 Hydrocarbons: ex. CH 4 Chlorinated hydrocarbons: ex. DDT Chlorinated hydrocarbons: ex. DDT Simple carbohydrates (simple sugars) ex. C 6 H 12 O 6 Simple carbohydrates (simple sugars) ex. C 6 H 12 O 6 Polymers = monomers linked together; 3 types 1. Complex carbohydrates 2. Proteins 3. Nucleic acids (DNA and RNA) Polymers = monomers linked together; 3 types 1. Complex carbohydrates 2. Proteins 3. Nucleic acids (DNA and RNA)

Atoms Subatomic particles Subatomic particles ProtonsProtons NeutronsNeutrons ElectronsElectrons Atomic number = # of protons Atomic number = # of protons Mass number = # neutrons + # protons Mass number = # neutrons + # protons Isotopes = elements w/ same atomic number, but different mass number (different # neutrons) Isotopes = elements w/ same atomic number, but different mass number (different # neutrons)

Subatomic particles interaction Animation

Atomic number, mass number interaction Animation

Matter Quality High-quality matter- concentrated, found near earth’s surface, useful High-quality matter- concentrated, found near earth’s surface, useful Low-quality matter - dilute, not easily accessible, not useful Low-quality matter - dilute, not easily accessible, not useful Material efficiency (resource productivity) = total amount of material needed to produce each unit of good or service - Area for improvement Material efficiency (resource productivity) = total amount of material needed to produce each unit of good or service - Area for improvement

Changes in Matter Physical - chemical composition not changed Physical - chemical composition not changed Chemical - chemical composition changed Chemical - chemical composition changed In text on page 26 Chemical Reaction of Burning Carbon

Law of Conservation of Matter Matter is not destroyed Matter is not destroyed Matter only changes form Matter only changes form There is no “throwing away” There is no “throwing away”

Matter and Pollution Harm Caused by Pollution Dependent on 3 factors: 1. Chemical nature of pollutants 2. Concentration 3. Persistence = length of time pollutant stays in air, water or body Harm Caused by Pollution Dependent on 3 factors: 1. Chemical nature of pollutants 2. Concentration 3. Persistence = length of time pollutant stays in air, water or body Degradable (nonpersistent) pollutants - broken down by natural processes Degradable (nonpersistent) pollutants - broken down by natural processes Biodegradable pollutants - broken down by decomposers (sewage) Biodegradable pollutants - broken down by decomposers (sewage) Slowly degradable (persistent) pollutants - take decades or longer to degrade (plastics, DDT) Slowly degradable (persistent) pollutants - take decades or longer to degrade (plastics, DDT) Non-degradable pollutants - not broken down by natural processes (Pb, Hg, As) Non-degradable pollutants - not broken down by natural processes (Pb, Hg, As)

Nuclear Change Natural radioactive decay - unstable isotopes emit matter and/or high-energy radiation Natural radioactive decay - unstable isotopes emit matter and/or high-energy radiation Radioactive isotopes (radioisotopes) Radioactive isotopes (radioisotopes) Half-life (about 10 half lives for radioactive waste to be safe) Half-life (about 10 half lives for radioactive waste to be safe) Radiation (alpha, beta, and gamma) - exposure can alter DNA, damage tissue, cause burns, miscarriages, cataracts, and cancer Radiation (alpha, beta, and gamma) - exposure can alter DNA, damage tissue, cause burns, miscarriages, cataracts, and cancer

Nuclear Reactions Fig. 2-7, p. 28 Fig. 2-6, p. 28 FissionFusion

Fig. 2-6, p. 28 Stepped Art Neutron Uranium-235 Fission fragment Fission fragment Energy n n n n n n Uranium-235 Nuclear (Fission) Chain Reaction

Fig. 2-7, p. 28 Nuclear (Fusion) Chain Reaction Fuel Reaction conditions Products Energy 100 million °C Neutron Proton Hydrogen-2 (deuterium nucleus) Helium-4 nucleus Hydrogen-3 (tritium nucleus)

Nuclear Fission Critical Mass = amount of fissionable nuclei needed to sustain a chain reaction Critical Mass = amount of fissionable nuclei needed to sustain a chain reaction Chain Reaction = releases an enormous amount of energy Chain Reaction = releases an enormous amount of energy

Nuclear Fusion Uncontrolled - thermonuclear weapons Uncontrolled - thermonuclear weapons Controlled - produce heat for electricity still experimental Controlled - produce heat for electricity still experimental

Energy Definition: The ability to do “work” and transfer heat Definition: The ability to do “work” and transfer heat Types: kinetic and potential Types: kinetic and potential Electromagnetic radiation: wavelength and energy content Electromagnetic radiation: wavelength and energy content

Martian doing mechanical work Animation

Sun High energy, short wavelength Wavelength in meters (not to scale) Low energy, long wavelength Ionizing radiationNonionizing radiation Cosmic rays Gamma rays X rays Near ultraviolet waves Far ultraviolet waves Near infrared waves Far infrared waves microwaves TV waves Radio waves visible waves Fig. 2-8, p. 29 Electromagnetic Spectrum All electromagnetic energy travels at 186,000 miles per second

Very high High Moderate Low Electricity Very high temperature heat (greater than 2,500°C) Nuclear fission (uranium) Nuclear fusion (deuterium) Concentrated sunlight High-velocity wind High-temperature heat (1,000–2,500°C) Hydrogen gas Natural gas Gasoline Coal Food Normal sunlight Moderate-velocity wind High-velocity water flow Concentrated geothermal energy Moderate-temperature heat (100–1,000°C) Wood and crop wastes Dispersed geothermal energy Low-temperature heat (100°C or lower) Very high-temperature heat (greater than 2,500°C) for industrial processes and producing electricity to run electrical devices (lights, motors) Mechanical motion (to move vehicles and other things) High-temperature heat (1,000–2,500°C) for industrial processes and producing electricity Moderate-temperature heat (100–1,000°C) for industrial processes, cooking, producing steam, electricity, and hot water Low-temperature heat (100°C or less) for space heating Relative Energy Quality (usefulness) Source of EnergyEnergy Tasks Fig. 2-10, p. 31 Energy Quality

First Law of Thermodynamics Energy is not created or destroyed Energy is not created or destroyed Energy only changes form Energy only changes form Can’t get something for nothing Can’t get something for nothing Energy input = Energy output Energy input = Energy output

Total energy remains constant Animation

Second Law of Thermodynamics In every transformation, some energy quality is lost In every transformation, some energy quality is lost You can’t break even in terms of energy quality You can’t break even in terms of energy quality Second Law greatly affects life Second Law greatly affects life

Examples of the Second Law Cars: only 20-25% gasoline produces useful energy Cars: only 20-25% gasoline produces useful energy Ordinary light bulb: 5% energy is useful light, rest is low-quality heat Ordinary light bulb: 5% energy is useful light, rest is low-quality heat Living systems: quality energy lost with every conversion Living systems: quality energy lost with every conversion

Solar energy Chemical energy (photosynthesis) Chemical energy (food) Mechanical energy (moving, thinking, living) Waste heat Waste heat Waste heat Waste heat Fig. 2-11, p. 32 Second Law of Thermodynamics

Energy flow animation Animation

Matter and Energy Change: Laws and Sustainability Unsustainable high-throughput (high- waste) economies Unsustainable high-throughput (high- waste) economies Matter-recycling-and-reuse economy Matter-recycling-and-reuse economy Sustainable low-throughput (low-waste) economies Lessons from Nature: Low- throughput Economy Sustainable low-throughput (low-waste) economies Lessons from Nature: Low- throughput Economy

Economic types interaction Animation