Return to Chemistry IndexCONSERVATION OF ENERGYRuby Bowen Hyde Park Career Academy 6220 South Stony Island Chicago, IL 60637 1-312-947-7237Objective:To demonstrate the law of the conservation of energy(blocks) without counting the units of energy directly.Materials:Blocks(At least 16 blocks per group); Box(Suitable to hold several blocks); Beaker(Large enough to hold several blocks); Ruler; BalanceStrategies:The following story contains several dilemmas. Each dilemma can be solved by an equation based on your knowledge of measurement, and your knowledge of the physical properties of matter.STORY:A young mother, wanting to keep up with the number of blocks her plays with in his room decides to keep a daily count of the total which is sixteen blocks. All of the blocks are the same size and shape. In order to keep up with the number of blocks her son has, she develops the following equation: Number of Visible Blocks = 16. The total number of visible blocks is constant with the number 16. So this would be a true equation. The above equation works fine for a while, until one day she counts the number of blocks and finds that there are only fourteen visible blocks in the room. The mother searches the room thoroughly but she cannot find the missing blocks. The frustrated mother is about to give up when she notices a trunk(box) under her son's bed. She becomes even more frustrated when she finds out that the trunk is locked and her son does not have a key. So she waits for a day when she can account for the total number of blocks and revises her old equation? Remember the total number of blocks is sixteen. Your(the mother's) equation is: _____________________________________________________________________ This equation works fine for a while, until the mother takes another look around the room and notices a large pail(beaker) filled with a green, murky liquid. She does not want to stick her hands into the liquid to find out if the pail contains the missing blocks so she again revises her old equation. One observation she makes is that the liquid measures about half full in the pail. How can the mother determine if the blocks are in the pail? Experiment as before, then revise the second equation. Remember the total number of blocks! This equation, too, works fine for a while, and she is thoroughly convinced that she has looked everywhere, when she happens to look out of the window. There, she notices two blocks on the lawn. So she adds these blocks to the total count and revises her equation again. OOPS! What do you believe has happened here? Can you develop an equation that would prove true for the mother? HINT: No blocks can be created or destroyed! Teachers: This experiment can be expanded to include the following concepts: 1. The relationship of mass vs. volume. 2. Density, specific gravity problems. 3. Law of the Conservation of Mass or Atoms. The main idea of this lesson is to emphasize conservation. Many topics covered in Chemistry(i.e. balancing equations, energy exchanges in chemical reactions, etc.) requires that this concept be understood. Yet, too many times the student does not understand, leaving large gap when introducing a new concept.