10. Which of the following is a property of mixture? a. It has a definite composition. b. It consists of a single phase. c. It has a heterogeneous composition. d. It can be chemically separated into its components. 11. Which of the following is a physical appearance of a substance? a. complicated b. homogeneous c. heterogeneous d. non-uniform 12. Which one is the best way to determine whether an unknown sample is a substance or a mixtura? a. Knowing its density b. Tasting the given sample c. Observing its physical appearance d. Testing its melting and boiling point 13. Which is NOT a technique to separate components of mixture? a. condensation b. distillation c. evaporation d. filtration 14. Which of the following is a heterogeneous mixture? a. air b. oil in water c. stainless steel d. soft drink 15.What is/are true for substance and mixture? 1. Pure substance melts completely. II. Pure substance has a varying boiling point. III. Mixture does not melt completely. IV. Mixture has a fixed boiling point. a. I and II only b. I and III only c. II and IV only d. I and IV only