An investigation was conducted to determine if Sn atoms could be substituted for Si atoms in the compound Cr₃Si. Prom size factor considerations, the feasibility that this substitution should occur seemed reasonable. However, attempts to make the substitution were unsuccessful. A model of the Cr₃O-type compounds, of which Cr₃Si is a representative, is proposed. From this model substitution of a Sn atom for a Si atom would require the formation of a double bond. The possibility of this double bond being unable to form may explain the unsuccessful attempts to make the above substitution. / Master of Science