1. Provide the key term that corresponds to each of the following definitions. (a) matter having an indefinite composition and properties that can vary within the sample (b) matter having a definite composition but properties that can vary from sample to sample; examples include alloys and solutions (c) matter having constant composition with definite and predictable properties (d) a pure substance that can be broken down into two or more simpler substances by chemical reaction (e) a pure substance that cannot be broken down any further by chemical reaction (f) a characteristic of the substance that can be observed without changing its chemical formula a characteristic of a substance that cannot be observed without changing its chemical formula (h) a modification of a substance that does not alter its chemical composition (i) a modification of a substance that alters its chemical composition (i) an insoluble solid substance produced from a reaction in aqueous solution Key Terms: chemical change, chemical property, compound, element, heterogeneous mixture, homogeneous mixture, physical change, physical property, precipitate, substance 2. Classify the following characteristics as a physical (phys) or chemical (chem) property. (a) physical state (b) density (c) melting point (d) hardness (f) reactivity (h) conductivity (e) appearance (g) solubility 3. Classify the following observations as a physical (phys) or chemical (chem) change. (a) candle burning (b) wax melting (c) alcohol vaporizing (e) apple turning brown (g) fire releasing heat (d) antacid fizzing in water (f) steam condensing on a mirror (h) fireworks releasing light 4. What is the purpose of the boiling chip when determining the boiling point of a liquid? 5. What experimental observations indicate a chemical change is taking place? 6. What experimental observations indicate a gas is being released? 7. What safety precautions must be observed in this experiment?