A platinum mesh electrode is used to introduce atoms of this element into a sample material in a method called "cathode charging." Above 400 degrees Celsius, atoms of this element react with steel (15[1])in a mechanism termed "high-temperature attack." By lowering the dislocation activation energy, (15[1])atoms of this element enhance "localized plasticity." Atoms of this element diffuse into (15[1])the microstructure of an alloy in a mechanism (-5[1])called (*) "embrittlement." (10[1]-5[1])At room (-5[1])temperature (-5[1])and pressure, palladium adsorbs (10[1]-5[1])nearly 1000 times its volume (10[1])in this element. (10[2])Either (10[1])carbon monoxide or this element reacts with iron ores to produce elemental iron in "direct reduction." A metallic phase of this element is believed (10[1])to exist (10[1])in (10[1])the extremely (10[1])high (10[1])pressures (10[2])of Jupiter and Saturn's cores. (10[2])For 10 points, (10[1])name this lightest element (10[2])on the periodic (10[1])table. (10[2]) (10[2])■END■