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.