There are two overarching types of assessment in educational settings: informal and formal assessments. Both types are useful when used in appropriate situations. Informal assessments are those assessments that result from teachers' spontaneous day-to-day observations of how students behave and perform in class.
In the chemical industry it is used to heat reactants and in processes such as distillation, product drying, electrolysis, and treatment of waste. At present, the energy used still relies mainly on fossil fuels, but even so the use of these can be reduced in several ways (Table 2).
A chemical decomposition reaction or analysis reaction is one of the most common types of chemical reactions. In a decomposition reaction a compound is broken into smaller chemical species. AB â A + B. The electrolysis of water into oxygen and hydrogen gas is an example of a decomposition reaction : 2 H 2 O â 2 H 2 + O 2. Another example is the decomposition of potassium chloride into potassium and chlorine gas. 2 KCl (s) â 2 K (s) + Cl 2 (g).