Write the following syllogisms in standard form and tell whether...

Write the following syllogisms in standard form and tell whether they are valid or invalid. If the latter, tell why (Hint: make sure there are three terms in the syllogism)

1.All human beings are mortal beings, for no human beings are eternal beings, and no eternal beings are immortal beings.

2.All mortals are imperfect beings, and no humans are immortals, whence it follows that all perfect beings are nonhumans.

3.Some metals are rare and costly substances, but no welder's materials are nonmetals; hence some welder's materials are rare and costly substances.

4.All things absent are non pleasurable things; therefore no pleasurable things are none the real things, because all ethereal things are present things.

5.All things inflammable are unsafe things, so all things that are safe are nonexplosives, since all explosives are combustable things.