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 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 b ab the combination of iron and sulfur to form iron ii sulfide is an example of a synthesis reaction 8 fe s 8 8 fes chemical decomposition or analysis reaction in a decomposition reaction a compound is broken into smaller chemical species