Module 4 Vocabulary

123456789
Across
  1. 4. to use a code to convert letters to symbols
  2. 5. when light rays from a source reflect off an object to the eye
  3. 6. when light shines on an object
  4. 8. to code to convert symbols to letters
Down
  1. 1. when light rays from a source off one or one
  2. 2. to send out a signals (by radio waves)
  3. 3. the natural agent that stimulates sight and makes things visible
  4. 6. rays a model of light that represents the direction
  5. 7. a system of signals or symbols used to communication
  6. 9. to give off light