Using the periodic table, predict the classification of iodine and elaborate on the reasoning. a) iodine is a noble gas and has a full valence electron shell, is chemically non-reactive, colorless, odorless, and is a gas at room temperature. b) iodine is a metal and is shiny, malleable, ductile, conducts heat and electricity, forms basic oxides, and forms cations in aqueous solution. c) iodine is a nonmetal and is dull, brittle, poor conductor of heat and electricity, forms anions in aqueous solution, and is a solid at room temperature. d) iodine is a metalloid and has properties of both metals and nonmetals - it appears lustrous, but is brittle and a poor conductor of heat and electricity.