Circle the synonym (=word that means the same): The right answer is underlined. 1. Chemists study the composition of natural substances. a. materials b. machines 2. Plastic products are hard to dispose of because they are almost indestructible. a. unable to be destroyed b. unable to be constructed 3. Silicon is a nonmetallic element that is inexpensive because it is so abundant in minerals and rocks. a. rare b. plentiful 4. When exposed to air and moisture, iron will corrode. a. rust b. shine 5. After the fire, the police investigated the cause of the combustion. a. burning b. excitement 6. Gasoline should be stored carefully because it is flammable. a. fireproof b. able to catch fire easily 7. Heat can convert a solid to a liquid. a. condense b. change 8. The ammonia was diluted in water to make it weaker. a. thinned b. thickened 9. A catalyst speeds up a chemical reaction. a. chemical agent b. forest animal 10. To obtain aluminum, metallurgists must extract it from bauxite. a. remove b. destroy 11. The temperature on a Fahrenheit fever thermometer ranges from 94° to 108°. a. extends b. contracts 12. The volume of air in a room can be measured in cubic feet. a. quality b. quantity 13. Ten minus four equals six. a. less b. plus 14. Newton computed the weights of the planets. a. measured b. calculated 15. Water contains hydrogen and oxygen in a ratio of two to one. a. proportion b. size 16. The price of gasoline was quadrupled, and there were fears it would go even higher. a. multiplied by four b. divided by four