Task: Text Categorization
Input (English): Question: By heating in electric furnaces of silica, calcium carbide and coal, calcium silicides are obtained. One of them: 
 Options:  <0> It has the composition CaSi2. <1> It does not react with water. <2> Does not react with sulfuric acid. <3> It is a powerful oxidizing agent. <4> Its reaction with liquid water generates calcium silicate.
Output (English): chemistry