1.which of the following is true about all mixtures? a). mixtures consist of two or more substances chemically combined. b). mixtures cannot be separated by physical means. c). mixtures consist of only one kind of atom. d). mixtures have two or more substance mixed together, but are not chemically combined. 2.the substances in a(n) mixtures are usually easily seen and separated. a). homogeneous b). heterogeneous c). uniform d). uncontaminated