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).
A chemical reaction is a process that is usually characterized by a chemical change in which the starting materials (reactants) are different from the products. Chemical reactions tend to involve the motion of electrons, leading to the formation and breaking of chemical bonds. An acid-base reaction is type of double displacement reaction that occurs between an acid and a base. 2  The H + ion in the acid reacts with the OH-ion in the base to form water and an ionic salt: 3  HA + BOH â H 2 O + BA. 4  The reaction between hydrobromic acid (HBr) and sodium hydroxide is an example of an acid-base reaction: