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