Phase changes - for example, when a solid becomes a liquid or a liquid becomes a gas - also indicate a physical change. Physical changes can be indicated by changes in a substance’s texture, shape, temperature or amount. Using the examples given, discuss what indicators you can use to determine whether a physical or chemical change has taken place. Chemical changes alter the chemical makeup of a substance, creating new substances when chemical bonds are broken and new chemical bonds form.ģ. Also, these changes are often reversible. The same substance is present before and after the physical change. Physical changes do not change the chemical composition of a substance. What happens to matter when it goes through a physical change? What about a chemical change? Using your answers, write your own definition of physical change and chemical change. The objects listed in the first example are going through physical changes, and the objects in the second set are going through chemical changes.Ģ. Look at the examples given below and discuss which group of examples you think show physical changes and which show chemical changes.Ĭrumbling paper, dissolving sugar, melting ice, bending a metal earring and diluting orange juice with waterĪ piece of paper burning, a car door rusting, food digesting, a banana ripening and a leaf photosynthesizing When matter goes through a change, the process is either classified as chemical or physical. A version of the article, “Chemists Crack the Code to Ancient Roman Concrete,” appears in the Februissue of Science News.ġ. Have students discuss the first set of questions with a partner, then read the Science News article “ These chemists cracked the code to long-lasting Roman concrete” and answer the second set of questions. Before beginning this work, students should understand that substances are made up of atoms, elements and molecules. This discussion activity can be used to help students better understand the difference between physical and chemical changes.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |