stances. A group of atoms that acts as a unit is called a(n) C. element. A. mixtures. B. molecule. D. compound. 5. Which of the following statements is TRUE? 4. Elements are the only kind of matter that can be properly classified as pure sub- B. Only pure matter is classified as substance, which includes only elements and compounds. c. All mixtures can easily be identified as impure, since the components are always easily recognizable. D. All solutions consist of a solid dissolved in a liquid. 0.5​