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MATTER AND ENERGY

MATTER AND ENERGY. CHAPTER TWO. What is matter? . Two chemical forms of matter: Elements Compounds What is a mixture? How many known elements are there? How many are naturally occurring? How are elements represented?. STATES OF MATTER. The smallest unit of matter is ___?

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MATTER AND ENERGY

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  1. MATTER AND ENERGY CHAPTER TWO

  2. What is matter? • Two chemical forms of matter: • Elements • Compounds • What is a mixture? • How many known elements are there? • How many are naturally occurring? • How are elements represented?

  3. STATES OF MATTER

  4. The smallest unit of matter is ___? What is an ion? What is a molecule and how are they held together? What are subscripts and what do they represent? The three physical states of matter on earth are____. Other facts about matter:

  5. Major parts of the atom are: Protons Neutrons Electrons The protons and neutrons form the ___ Electrons are located in ____ What is the atomic number? What is the mass number? What are isotopes? How do you identify isotopes in the symbol? The Atom

  6. ISOTOPES

  7. What does a chemical formula tell you? What are the characteristics of ionic bonds? What is an example of an ionic bond? What are covalent bonds? What is an example of a covalent bond? What are hydrogen bonds? What is an example of a hydrogen bond compound? Holding atoms together

  8. Covalent bonds

  9. Other important compounds

  10. Hydrogen bonds

  11. What element do all organic compounds contain? What other elements can be also combined? Organic compounds can be natural or synthetic. Most organic compounds are covalent bonds. What are organic compounds?

  12. Hydrocarbons made up of ___ Chlorinated hydrocarbons An example would be: Chlorofluorocarbons - An example would be: Simple carbohydrates Monomers Polymers Complex carbohydrates Proteins Nucleic acids Types of organic compounds:

  13. ALPHA-AMINO ACIDS - 20 DIFFERENT MONOMERS - # & SEQUENCE SPECIFIED BY GENETIC CODE IN DNA MOLECULES IN CELLS NUCLEIC ACIDS - DNA & RNA - MADE BY LINKING MONOMERS CALLED NUCLEOTIDES TOGETHER MORE ON PROTEINS:

  14. GENES - SEUQENCES OF NUCLEOTIDES - CARRIES A CODE WHICH CONTAINS TRAITS PASSED FROM PARENTS TO OFFSPRING GENOME - ALL OF THE GENETIC INFORMATION FOR AN ORGANISM. What are GENE MUTATIONS? What are CHROMOSOMES?

  15. Some important elements • Composition of the earth’s crust • Inorganic compounds • All compounds that do not contain carbon • Crust - outermost layer of earth - mainly inorganic minerals and rocks

  16. A measure of how useful a matter resource is - based on availability and concentration High quality matter -organized, concentrated and usually found near earth’s surface Low quality - disorganized, dilute,often deep underground or dispersed in the ocean or atmosphere - have little potential use as a matter resource. Matter quality

  17. Matter Quality

  18. WHAT IS ENERGY? • What is ENERGY ? • What is WORK? • What is a FORCE? • Forms of energy - light, heat, electricity, chemical energy, mechanical energy, and nuclear energy

  19. What is Kinetic energy? What does it depend on? Examples: wind, flowing water, electricity, electromagnetic radiation, heat, temperature What is Potential energy? What does it depend on? Potential energy changes into kinetic energy etc. Types of energy

  20. Electromagnetic spectrum • Transverse waves • Different wavelengths and frequencies • Ionizing radiation - harmful forms of electromagnetic radiation • Non-ionizing radiation - does not contain enough energy to form ions

  21. Temperature • What is temperature? • The average speed of the motion of the molecules in a given sample of matter • What is heat? • The total kinetic energy of all the moving molecules within a given substance

  22. How is heat transferred? • What is convection? • What is Conduction? • What is Radiation?

  23. Energy quality • An energy source’s ability to do useful work • High-quality - organized or concentrated - can perform useful work • Electricity, coal, gasoline, sunlight,uranium • Low - quality - disorganized or dispersed- can perform little useful work • Heat in water, air, etc.

  24. What is a Physical change? What are some examples of physical changes? All changes involve energy - taken in or released What is a Chemical change ? What is an example? What is a CHEMICAL Equation? Reactants --> products Changes in matter

  25. Law of Conservation of Matter • All the matter on earth is here and cannot be “thrown away” - there is no “away” • Earth is a closed system • Matter cannot be created nor destroyed • Matter is not consumed

  26. Nuclear changes • Natural radioactivity- when nuclei of certain isotopes spontaneously break down into one or more different isotopes • Three types: • 1. Natural radioactive decay • 2. Nuclear fission • 3. Nuclear fusion

  27. Law of Conservation of matter and energy • Applies to nuclear changes because a certain amount of mass (matter) is changed into energy. • The TOTAL amount of matter and energy involved remains the same

  28. Severity of their effects depends on: Chemical nature Concentration Persistence Three categories: Degradable – nonpersistent Biodegradable Slowly degradable - Presistent Nondegradable What are Pollutants?

  29. Changes in the nucleus of the atom Three types: Natural radioactive decay Nuclear fission Nuclear fusion Nuclear Changes

  30. Unstable isotopes - radioisotopes - spontaneously break down and emit: Alpha particles - positively charged helium nuclei Beta particles - high speed electrons Gamma rays - high speed ionizing electromagnetic radiation Natural radioactive decay

  31. Half-life • Rate of decay • Time needed for one half of the nuclei in a radioisotope to decay and emit their radiation • Eventually forms a new element • Is not affected by temp. pressure, chemical changes, etc. • Rule is store for 10 half-lives for safety

  32. Nuclear fission • Nuclei of atoms with large mass numbers are split into lighter nuclei • Neutrons used to split • Releases more neutrons and energy • Critical mass - needed to start reaction

  33. More on fission • Atomic bombs - uncontrolled nuclear fission • Damage cells • Used in nuclear power plants

  34. Nuclear fusion • Two isotopes of light elements are combined under great heat and pressure to form a heavier nucleus • Harder to initiate • Thermonuclear weapons

  35. Ionizing Radiation – from natural or background sources • Can come from space, soil, food, etc. • Has energy to knock electrons from atoms • Can disrupt living cells, interfere with body processes and cause cancer. • Nonionizing radiation doesn not contain enough energy to form ions.

  36. First law of thermodynamics • In all physical and chemical changes, energy is neither created nor destroyed but it may be converted from one form to another • Energy input always equals energy output • You can’t get something for nothing - cannot get more energy out of a system than is put in!!!

  37. Second law of thermodynamics • When energy is changed from one form to another, some useful energy is always degraded to lower quality less useful energy usually heat lost to the environment • We ALWAYS end up with less useful energy than we started with. • An incandescent light bulb - 5 % light, 95% heat

  38. More on 2nd law • We can NEVER recycle or reuse high quality energy to do useful work. • You get high quality matter and energy in your body, you use it and you add low quality waste matter and heat to the environment.

  39. What is energy efficiency? • A measure of how much useful work is accomplished by a particular input of energy into a system • Always measured as a percent (%) • Affects life because you get and use high quality matter and energy , use it and add low quality heat and waste back into the environment.

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