1. Which of the following is a compound?   Sodium sulfide solution   Sodium sulfide   Sodium   Hint Half-n-half Clue   2. Which of the following is a mixture?   Potassium   Potassium carbonate solution   Potassium carbonate   Half-n-half Clue   3. Which of the following is a pure substance made up of two or more types of atoms or elements?   Mixture   Element   Compound   Half-n-half Clue   4. Potassium sulfide solution is a _______ mixture.   heterogeneous   homogeneous   5. Oxygen cannot be further subdivided into simpler substances by any physical or chemical means. Therefore, it is _______.   an element   a mixture   a compound   Half-n-half Clue   6. Stainless steel is a mixture (alloy) of _______, _______, chromium, and nickel.   lead, magnesium   aluminum, tin   copper, zinc   iron, carbon   Half-n-half Clue   7. Which of the following is an element?   Calcium   Calcium chloride solution   Calcium chloride   Half-n-half Clue