[ 469 ] Physical Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Refer to the following passage to answer the next three questions. Oxygen is a very corrosive substance and will combine with many other substances or oxidize other substances. A common example is that of a piece of iron left out in the air. Over time, the iron rusts. The rust is a chemical change and can be described by a chemical reaction. Four atoms of solid iron (Fe) combine with three molecules of gaseous oxygen (O 2 ) from the air to form two molecules of solid iron oxide (Fe 2 O 3 ). The chemical reaction can be written by this chemical equation: 4 Fe (s) + 3 O 2 (g) → 2 Fe 2 O 3 (s) This class of chemical reaction is called a combination reaction. Using the information presented in the passage, assign each substance’s symbol to its name. Iron Oxygen Iron Oxide •O 2 • Fe 2 O 3 • Fe According to this passage, what does the word oxidize mean?