Name an element in the fourth period (row) of the periodic

 Ionian Enlightenment  Thales, 585 BC  Proposed water was basic stuff  Anaximander, 565 BC  Thought that the ultimate stuff couldn’t be identified w/ any known thing; called Aperion or boundless  Anaximenes, 545 BC  Thought air was the basic material; all manifest matter was the result of “refraction” or “condensation”  World was understandable in terms of natural phenomena  “Stuff in the world” must be composed of the same “substance”  Zeno’s Paradox (Zeno of Elia)  Series of paradoxes to explain infinity  Denies possibility of motion from one point to another  Is matter discrete or continuous  Democritus of Abdena  Father of atomism  Idea that there is an ultimate, uncuttable constituent of all matter  “Nothing exists but atoms and the void. All else is opinion”  Aristotle  Founder of formal logic  Found the idea od the void rationally repugnant and matter was continuous  5 basic elements: earth, fire, water, air, and the aether  Basic logic and scientific method  Humans get conclusions by logical process using arguments  Argument 1: If an obj. is a car, then it has wheels. That obj. has wheels, therefore it is a car  Invalid  Induction  Inferring a general principle based on specific obs.  “If A, then B. B, therefore A” (B A)  Argument 2: if an obj. is a car, it has wheels. That obj. is a car, therefore it has wheels  Valid