Mystery Words: Periodic Puzzle!

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Across
  1. 1. It means a pattern that we can observe across the periodic table.
  2. 4. It is a row in the periodic table.
  3. 6. Atomic ______ is the size of an atom or the distance from the nucleus to the outermost electron.
Down
  1. 2. These are tiny particles that move around the nucleus.
  2. 3. It is the building block of matter.
  3. 5. It is a column in the periodic table.