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Multiple choice questions lend themselves to the development of objective assessment items, but without author training, questions can be subjective in nature. Because this style of test does not require a teacher to interpret answers, test-takers are graded purely on their selections, creating a lower likelihood of teacher bias in the results. [8]
Chemistry is the scientific study of the properties and behavior of matter. [1] It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances.
The IUPAC's rules for naming organic and inorganic compounds are contained in two publications, known as the Blue Book [1] [2] and the Red Book, [3] respectively. A third publication, known as the Green Book , [ 4 ] recommends the use of symbols for physical quantities (in association with the IUPAP ), while a fourth, the Gold Book , [ 5 ...
A different chemistry-based approach advocates replacing the term "heavy metal" with two groups of metals and a gray area. Class A metal ions prefer oxygen donors; class B ions prefer nitrogen or sulfur donors; and borderline or ambivalent ions show either class A or B characteristics, depending on the circumstances. [32]
For example, the three isomers of xylene CH 3 C 6 H 4 CH 3, commonly the ortho-, meta-, and para-forms, are 1,2-dimethylbenzene, 1,3-dimethylbenzene, and 1,4-dimethylbenzene. The cyclic structures can also be treated as functional groups themselves, in which case they take the prefix "cyclo alkyl -" (e.g. "cyclohexyl-") or for benzene, "phenyl-".
The fact that how fast reactions occur can often be specified with just a few concentrations and a temperature, instead of needing to know all the positions and speeds of every molecule in a mixture, is a special case of another key concept in physical chemistry, which is that to the extent an engineer needs to know, everything going on in a ...
General chemistry (sometimes referred to as "gen chem") is offered by colleges and universities as an introductory level chemistry course usually taken by students during their first year. [1] The course is usually run with a concurrent lab section that gives students an opportunity to experience a laboratory environment and carry out ...
DNA encoded chemical libraries (DECLs) are synthesized by the combinatorial chemistry principle and it clearly agrees with their application. [5] Fig. 1 DNA-encoded library displaying chemical compounds Schematic representation of DNA-encoded library displaying chemical compounds directly attached to oligonucleotides. a) Library generated by ...