matter

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Across
  1. 3. firm and stable in shape; not liquid or fluid.
  2. 6. the average kinetic energy of all the atoms or molecules of that substance
Down
  1. 1. a substance or matter in a state in which it will expand freely to fill the whole of a container,
  2. 2. heat energy
  3. 4. is a fluid (such as water) that has no independent shape
  4. 5. anything that occupies space