How do you evaluate an argument for soundness

An argument is a list of statements called premises given in support of a final statement called the conclusion.  Consider, for example, the following argument.    1.  Socrates is a person;   2.  All persons are mortal; therefore,   3.  Socrates is mortal.  Statements (1) and (2) are this argument’s premises and statement (3), which “follows” from (1) and (2), is its conclusion. Two properties are relevant to evaluating arguments:  validity and soundness.        •  Arguments are valid when it is the case that if their premises are true, then their conclusions must also be true.        •  Arguments are sound when it is the case that they are both valid and all of its premises are true. 

A triple beam balance is a type of scale commonly used in the laboratory to determine the mass of samples. To use the balance, you use sliding weights called riders on three beams, each with progressively small incremental amounts. 

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