No form of elemental silicon is comparable to graphite.

1.	No form of elemental silicon is comparable to graphite.
Answer» Solution :In graphite, carbon is `sp^(2)`-hybridizedand eachcarbon is liked to three other carbon atoms by forming hexagonalrings.Eachcarbonis now LEFT with on unhybridized p-orbital which undergoes sidewaysoverlap to form three `ppi-ppi`double bonds.Thus,graphite has two dimensional sheet like (layered) structureconsistingof a number of benzenerings fusedtogether. Siliconon the other hand,does notforman anlogue ofcarbon becauseof the FOLLOWING REASON : DUE to bigger size kand smallerelectronegativityof Si than C, it does not undergo `sp^(2)`-hybridization and hence it does not form`ppi-ppi`double bondsneededfor graphite like structure. Instead, it PREFERS to undergoonly `sp^(3)`-hybridization and hencesiliconhas diamondlike three-dimensional network structure.

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