1 / 15

An Introduction to Energy

An Introduction to Energy. Unit 2, Presentation 1. What is Energy?. Energy is defined as the ability to do work Work is any force applied over a distance. Six Different Types of Energy. *Nuclear Energy is a special case*. SI Unit for Energy. Energy is measured in Joules (J)

katelyn-hogan
Download Presentation

An Introduction to Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. An Introduction to Energy Unit 2, Presentation 1

  2. What is Energy? • Energy is defined as the ability to do work • Work is any force applied over a distance

  3. Six Different Types of Energy *Nuclear Energy is a special case*

  4. SI Unit for Energy • Energy is measured in Joules (J) • Named in honor of James Joule (British) • Can also be measured in Calories (cal) • One calorie = amount of energy needed to warm one gram of water one Kelvin. • One calorie ~ 4.20 Joules

  5. Conservation of Energy & Mass • Energy is neither created nor destroyed in a chemical reaction • Mass is neither created nor destroyed in a chemical reaction

  6. Types of Chemical Reactions • Exothermic: A chemical reaction that releases heat energy. Expressed as the following: Reactants  Products + Energy • Endothermic: A chemical reaction that absorbs heat energy. Endothermic reactions require heat energy to be completed. Expressed as the following: Reactants + Energy  Products

  7. Heat Energy and Temperature • Temperature is a measure of heat energy • Three measures of temperature: • Degrees Fahrenheit • Degrees Celsius • Kelvin (Absolute Temperature)

  8. Comparison of Three Temperature Scales

  9. Making a Celsius Thermometer

  10. Converting to Kelvin • The Absolute Temperature (Kelvin) scale is most often used • K = °C + 273.16 • Hence, 0.0000°C = 273.16K

  11. Calorimetry • Calorimetry: The measurement of the amount of heat released or absorbed during a chemical reaction.

  12. Calorimetry Example • A 2000. gram mass of water has its temperature raised 3.0°C while an exothermic chemical reaction is taking place. How much heat is transferred to the water by the heat of the reaction (the specific heat of water is 4184 J/kg K)?

  13. Another Calorimetry Example • A 1000. gram mass of water whose temperature was 50.0°C lost 33 600 J of heat over a 5-minute period. What was the temperature of the water at the end of the 5-minute period? Use the same specific heat of water as the previous example.

  14. Kinetic Theory of Heat & Temperature • Heat energy, measured by temperature, is directly proportional to the average kinetic energy of the molecules in the substance. • As temperature increases, so does the average speed of the molecules in the substance • As temperature decreases, so does the average speed of the molecules in the substance.

  15. More Kinetic Theory Matter consists of atoms and molecules in motion. Slow Molecules Fast Molecules Slow vibratory motions Still mostly vibrations, but slightly faster v Solid Liquid Gas Low Energy Moderate Energy High Energy

More Related