Use a comma to separate items in a series. Although placing afinal comma before the coordinating conjunction is oftenconsidered optional, omitting it can sometimes cause confusion. Consequently, most scientificand technical writing routinely uses a final comma in a series to prevent possible ambiguities.
His intellectual acuity, diverseinterests, frail physique, and etherealpersonality made Oppenheimer a man of legendary proportions.[In this sentence,omitting the final comma would not cause confusion. Still, it is good practice in scientific andtechnical writing to always include the final comma in a series.]
Contemporary physics is still exploring neutron stars, black holesand the penetration of electrons through potential barriers. [The omission of the final comma before and causes ambiguity: are black holes and thepenetration of electrons through potential barriers specific topics connected to the generalsubject of neutron stars, or are they separate items?]
Contemporary physics is still exploring neutron stars, black holes,and the penetration of electrons through potential barriers.
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