class 10 medium english science unit 1
“Facts are not science — as the dictionary is not literature.” Martin H. Fischer CHAPTER 1 Chemical Reactions and Equations C onsider the following situations of daily life and think what happens when – „ milk is left at room temperature during summers. „ an iron tawa/pan/nail is left exposed to humid atmosphere. „ grapes get fermented. „ food is cooked. „ food gets digested in our body. „ we respire. In all the above situations, the nature and the identity of the initial substance have somewhat changed. We have already learnt about physical and chemical changes of matter in our previous classes. Whenever a chemical change occurs, we can say that a chemical reaction has taken place. ...