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 occurs when chemicals combine to form new substances with new properties. Burning is a rapid type of chemical reaction that produces large amounts of heat and light. An example of a fast chemical reaction is an explosion, such as the exploding of fireworks or a bomb. An example of a slow chemical reaction is rusting (or oxidisation). One of the chemicals produced during burning is carbon dioxide, which we now refer to as a 'greenhouse gas'.