Let's look at a few assessment scenarios. Try to determine what type of assessment is being used, formal or informal. 1  Example 1. 2  A kindergarten teacher sets aside the first 15 minutes of every day to allow students to explore, play or engage in any activity of their choice.
Chemical bonds are made or broken in order to create a new molecule. One example of a chemical reaction is the rusting of a steel garbage can. That rusting happens because the iron (Fe) in the metal combines with oxygen (O2) in the atmosphere. Chemical bonds are created and destroyed to finally make iron oxide (Fe2O3).
â¢ CHEMICAL REACTION (noun). The noun CHEMICAL REACTION has 1 sense: 1. (chemistry) a process in which one or more substances are changed into others. Familiarity information: CHEMICAL REACTION used as a noun is very rare.hemical decomposition reaction; decomposition; decomposition reaction ((chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance). chemical equilibrium; equilibrium (a chemical reaction and its reverse proceed at equal rates).