Informal vs. Formal Assessments. In order to properly understand what informal assessments are, we should first differentiate them from formal assessments. Formal assessments are designed to tell how well a student has progressed as evaluated against other students.
Rusting of iron consists of the formation of hydrated oxide, Fe(OH) 3, FeO(OH), or even Fe 2 O 3 .H 2 O. It is an electrochemical process which requires the presence of water, oxygen and an electrolyte. In the absence of any one of these rusting does not occur to any significant extent.
Other forms of rust exist, like the result of reactions between iron and chloride in an environment deprived of oxygen â rebar used in underwater concrete pillars is an example â which generates green rust.lthough some people refer to rust generally as oxidation, that term is much more general; although rust forms when iron undergoes oxidation, not all oxidation forms rust. Only iron or alloys that contain iron can rust, but other metals can corrode in similar ways. The main catalyst for the rusting process is water.