Which one among the following statements regarding the properties of mixtures and compounds is not correct?
(a) A mixture shows the properties of its constituents but the properties of a compound are entirely different from its constituents
(b) A mixture may be homogeneous or heterogeneous but a compound is a homogeneous substance
(c) The constituents of a mixture can be separated by physical methods but those of a compound cannot be separated by physical methods
(d) Energy is either absorbed or evolved during the preparation of a mixture but not in the preparation of a compound