1.
An element E{B, C, Si, Ge}\text{E} \in \{\text{B, C, Si, Ge}\}. I: Powdered E reacts with O2\text{O}_2 to form an oxide. II: Oxide formed in I reacts with NaOH\text{NaOH}. III: E reacts with steam on red heat forming two gaseous products used as fuel. E can be: