Science crossword puzzel

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Across
  1. 3. Electron electrons on the outermost energy level of an atom that determine the reactivity of the atom.
  2. 5. Reaction A chemical reaction in which heat is released and usually feels warm when the heat is released from the reaction.
  3. 6. vertical column of elements on the Periodic Table that have similar physical and chemical properties.
  4. 7. elements that have some properties of metals and non-metals and are found along the zigzag on the Periodic Table.
Down
  1. 1. Reaction A chemical reaction that requires an input of energy and usually feels cold when it absorbs heat in the reaction.
  2. 2. horizontal row of elements on the Periodic Table that have the same number of electron shells.
  3. 4. Bond an interaction that holds atoms together.
  4. 8. of Conservation of Mass states that matter is neither created nor destroyed in ordinary chemical and physical changes.