1. ENERGY & MATTER Chapter 2

2. Learning Target List the different types of energy.

3. Learning Targets Know and apply the 3 basic forms of energy.

4. What is Energy? The capacity to do work or produce heat.

5. Law of Conservation of Energy Energy can neither be created nor destroyed in any chemical or physical process. It can be converted from one form to another.

6. 2-1 Energy Energy is classified into three main forms Radiant Kinetic & Potential

7. Radiant Energy This is energy from the Sun which is the result of nuclear fusion http://interestingenergyfacts.blogspot.com/ 2010/04/nuclear-fusion-facts.html

8. Kinetic Energy This is the energy carried by objects in motion, like a locomotive. Kinetic Energy includes: 1. Mechanical energy carried by the moving parts of a machine 2. Thermal Energy of the random internal motion of particles in all substances (This is what is measured with temperature)

9. Potential Energy This is the energy possessed by objects because of the position or the arrangement of their particles In essence it is stored energy.

10. Gravitational Potential Energy The kind of energy carried by water before it falls through the spillway of a hydroelectric dam is called gravitational potential energy. Gravity is responsible for converting the potential energy of the water into kinetic energy, which is then able to do work

11. Other forms of Potential Energy Electrical Energy is the energy that exists when objects with different electrical charges are separated. Batteries operate on this principle.

12. Chemical Energy This is the energy which exists in some substances because of the arrangement of their particles. Fuels and food contain chemical potential energy Other forms of Potential Energy

14. What unit of energy do you personally consume everyday? Know the energy units (Calories, calories, kilojoules, joules), and how to convert from one unit to another. Learning Target – 10/8/13

15. Calorie (cal) [older unit] The amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.

16. Example #1: How much energy is required to raise 31.0 g of water from 10°C to 25°C?

17. Energy stored in food is often given a unit that is related to the calorie. 1 Calorie (Cal) or 1 kilocalorie = 1000cal

18. James Joule English scientist in the mid-1800’s Known as the father of thermodynamics He found that changes produced by heating a substance could also be produced by mechanical energy He discovered the relationship between mechanical energy and heat energy and formed the basis for the Law of Conservation of Energy

19. The SI Unit of energy is the Joule (J) Joule (J) in the long form is kg. m 2 /s 2 4.184J = 1 cal 4.184 kJ = 1kcal or 1Cal 1 kJ = 1000 J 1 Cal or kcal = 1000 cal

20. 1cal =4.184 joules chocolate bar=200 Cal 200Cal x 4.184 kJ/Cal= Energy in one chocolate bar= 836.8kJ How many Joules? How many calories?

21. Learning Target Know the difference between Fahrenheit, Celsius, and Kelvin temperature scales and how to convert from one scale to another. Explain what is meant by Absolute Zero.

22. What is the difference between heat and temperature?

23. Thermal Energy (Heat) vs. Temperature Thermal Energy = sum total of all the KE of the particles in a sample. Temperature = measure of the average KE of the particles

24. Temperature Peak emittance wavelength [65] of black-body radiationwavelength [65]black-body radiation KelvinDegrees Celsius Absolute zero Absolute zero (precisely by definition) 0 K−273.15 °Ccannot be defined Coldest temperature achieved [66] [66] 100 pK−273.149999999900 °C29,000 km Coldest Bose–Einstein condensate [67] [67] 450 pK−273.14999999955 °C6,400 kmkm One millikelvin (precisely by definition) 0.001 K−273.149 °C 2.89777 m (radio, FM band) [68]FM band [68] WaterWater's triple point (precisely by definition)triple point 273.16 K0.01 °C 10,608.3 nm (long wavelength I.R.)I.R. Water's boiling point [A]boiling point [A] 373.1339 K99.9839 °C 7,766.03 nm (mid wavelength I.R.) Incandescent lamp [B] 2500 K≈2,200 °C 1,160 nm (near infrared) [C]infrared [C] Sun'sSun's visible surface [D][69] [D][69] 5,778 K5,505 °C 501.5 nm (green-blue light)green-blue light Lightning bolt's Lightning bolt's channel [E] [E] 28 kK28,000 °C 100 nm (far ultraviolet light)ultraviolet Sun's core [E] 16 MK16 million °C0.18 nm (X-rays)X-rays Thermonuclear weapon Thermonuclear weapon (peak temperature) [E][70] [E][70] 350 MK350 million °C 8.3×10 −3 nm (gamma rays)gamma rays Sandia National Labs' Z machine [E][71] Z machine [E][71] 2 GK2 billion °C 1.4×10 −3 nm (gamma rays) [F] [F] Core of a high-mass star on its last day [E][72]high-mass star on its last day [E][72] 3 GK3 billion °C 1×10 −3 nm (gamma rays) Merging binary neutron star system [E][73]neutron star [E][73] 350 GK350 billion °C 8×10 −6 nm (gamma rays) Relativistic Heavy Ion Collider [E][74] 1 TK1 trillion °C 3×10 −6 nm (gamma rays) CERN'sCERN's proton vs nucleus collisions [E][75] [E][75] 10 TK10 trillion °C 3×10 −7 nm (gamma rays) Universe 5.391×10 −44 s after the Big Bang [E]5.391×10 −44 sBig Bang [E] 1.417×10 32 K1.417×10 32 °C 1.616×10 −27 nm 1.616×10 −27 nm (Planck Length) [76] [76]

25. Thermometer The modern thermometer used in our class is filled with colored alcohol.

26. Fahrenheit Scale Daniel Fahrenheit developed the first alcohol thermomter in 1709 and the mercury thermometer in 1714 He divided the freezing and boiling points of water into 180 degrees. 32° F was freezing of water and 212° F was the boiling piont. 0° F was based on the temperature of water, ice and salt mixture.

27. Celsius Scale In 1742 Anders Celsius took 0° C for freezing of water and 100° C for the boiling point of water. He dividing these points into equal scales. Often referred to as the “centrigrade” scale which mean “divided into 100 degrees”

28. Kelvin Lord Kelvin used the same scale as Celsius to invent the Kelvin scale in 1848. He developed the theoretical idea of absolute zero and this became 0 K.

29. The Celsius Temperature Scale The freezing point of pure water at sea level is 0º C, 32°F, 273.15 K. The boiling point of pure water at sea level is 100ºC, 212°F, 373.15 K.

30. Kelvin Temperature Scale SI Unit for temperature is Kelvin (K). The degree unit is not used in Kelvin (K),

31. The Difference between Kelvin and Celsius The main difference is the location of the zero point. The zero point for kelvin is called absolute zero. Absolute zero is equal to -273º C or 0K. Absolute zero is the point at which the motion of particles of matter has completely stopped.

32. Converting Kelvin and Celsius ºC = K – 273 K = ºC + 273

33. Convert 50. K to the Celsius scale

34. Converting Fahrenheit to Celsius ºC = (ºF – 32) x 5/9 Convert 67°F to °C ºC = (67º – 32) x 5/9 = 19.4 ºC

35. Converting Celsius to Fahrenheit ºF = (9/5 x ºC) + 32 Convert -14 ºC to ºF ºF = (9/5 x -14º) + 32 = 6.8ºF

36. Learning Target 1) Name and describe the 4 states of matter 2) Describe the differences between a physical change and chemical change.

37. 3 States of Matter [Actually 4 States] Solid-definite shape & volume, maintains shape without a container. Liquid-definite volume but indefinite shape, takes the shape of its container but does not fill. Gas-indefinite shape & volume, fills any container placed in. Plasma-highly ionized form of gas that exists at high temps. (surface of the sun)

38. Physical Characteristics Physical Changes-These are observed or tested without changing the substance.

39. Physical Properties of Matter Extensive Properties- dependent on the quantity of matter. (mass, volume, shape) Intensive Properties-Not dependent on the size of the sample. (melting point, boiling point, density)

40. Chemical Characteristics Chemical Properties-How a substance reacts with other substances. This is observed in chemical reactions. Chemical Change-When a substance is converted into a new substance. All properties and characteristics will change! Format: Reactants  Products (start) (yields) (ending)

41. Inferences vs. Observations Observation: You use one or more of your five senses to know or determine something. Inference: You make an explanation for the observation. Example: You see steam rising off of a cup of coffee. (Observation) The coffee is hot. (Inference)

42. Indicators of Chemical Change 1. Evolution of heat and/or light. 2. Production of a gas (not from boiling) 3. Production of a precipitate (ppt.) (solid but not from freezing) 4. Color change (be careful with this one, indicators cause color change but that is not chemical!)

43. WARM UP A runner burns about 10 kcal per minute. If the runner completes a race in one hour and fourteen minutes, how many kJ did he burn? How many J did he burn?

44. Learning Targets 1) Compare physical and chemical properties of matter. 2) Explain the differences between elements, compounds, and mixtures. 3) Explain the difference between homogeneous and heterogeneous mixtures, and techniques to separate them.

45. Chemical Characteristics Chemical Properties-How a substance reacts with other substances. This is only observed in a chemical reaction. Chemical Change-When a substance is converted into a new substance. All properties and characteristics will change! Format: Reactants  Products (start) (yields) (ending)

46. Physical Characteristics Physical Properties-These are observed or tested without changing the substance. Physical change -These include changes of state such as melting, boiling, dissolving, grinding, filtering, etc.

47. Mixtures Mixture-Physical combination of 2 or more substances. 2 Classifications:  Heterogeneous-different composition present [examples: sand, granite, milk of magnesia]  Homogeneous-same composition present throughout [examples: salt water, Gatorade, coffee]

48. Separation of Mixtures separate mixtures based on different physical properties of the components EvaporationDissolves in water Filtration/Decanting State of Matter (solid/liquid/gas) DistillationBoiling Point TechniqueDifferent Physical Property

49. Distillation

50. Filtration

51. Evaporation Liquid vaporizes leaving less volatile liquid or solid.

52. Pure Substances Elements & Compounds  These always have the same properties  The same composition  They can not be separated without changing properties.

53. Element A substance that can not be broken down into another substance by chemical means. The smallest part is an atom There are approximately 90 naturally occurring elements.

54. Compound A substance that can be broken down into another substance by chemical means. The smallest part is a molecule or ion.

56. Kinetic Energy (KE) KE = ½ mv 2 Unit KE = kinetic energyJ = Joule (kg. m 2 /s 2 ) m = masskg v = velocitym/sec

57. Calculate the KE of a 70kg man walking at 2.5m/s.

58. Potential Energy (PE) Stored energy Gravitational Potential Energy –energy due to position PE = mghUnits PE = potential energyJ= Joule m = masskg g = force of gravity Earth = 9.8 m/sec 2 (CONSTANT) h = heightmeter

59. PE=m g h m=2kg h= 40m g=9.8m/s 2 PE = 2kg x 40m x 9.8 m/s 2 PE = 784 Joules What is the gravitational potential energy of a 2 kg ball at rest on a window sill, 40m up from the pavement?

60. WARM-UP PROBLEM Determine the kinetic energy for a 400 g ball traveling at 3.0 km/min. (Remember to convert g to kg and km/min to m/s.)

61. See sample problem #4 What is the minimum height the ball would need to be dropped from to achieve this velocity before impact with the ground?