Completely classify liquid FeFe. Pure Substance Compound Mixture Element Homogeneous Mixture Heterogeneous Mixture Solution liquid FeFe is an element because is a simplest type of a pure substance which is composed of only one type of matter. For examples; silver, gold platinum etc. Element: An element is a simplest type of a pure substance which is composed of only one type of matter. For examples; silver, gold platinum etc. Pure substance: A compound is a pure substance which is composed of two or more type of matter in definite proportion. For examples; water which is composed by Hydrogen and oxygen etc. Compound: A compound is a pure substance which is composed of two or more type of matter in definite proportion. For examples; water which is composed by Hydrogen and oxygen etc. Mixture: A mixture is made from two or more type of matter in any proportion. Mixture are generally two types: This is also known as solution, in which the composition of the substances is uniform. Lemon-flavored water is an example of homogeneous mixture because in this the composition of the substances is uniform. In this form of mixture the composition of substance are not uniform and the component of mixture also visible. Stuffed mushrooms is an example of Heterogeneous mixture because in this form of mixture the composition of substance are not uniform and the component of mixture also visible. .