Reactions

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Across
  1. 6. for combustion to occur you need to have heat, fuel and _______
  2. 7. before a fuel is burnt, energy is stored in the form of _______ energy
  3. 8. two or more different elements chemically bonded together
  4. 11. the scientific word for the process of burning
  5. 12. during a chemical reactions b_____ between atoms are formed and/or broken
  6. 14. during a chemical reaction mass is c_________ (kept the same)
  7. 15. the periodic table consists of _________.
Down
  1. 1. in the periodic table C is the symbol for ________
  2. 2. every atom is made of _______, neutrons and electrons
  3. 3. the substance(s) present before a chemical reaction
  4. 4. in the periodic table H is the symbol for ________
  5. 5. during a chemical reactions atoms are r_________
  6. 9. a state change (e.g. melting) is reversible and is therefore a ________ change
  7. 10. the substance(s) present after a chemical reaction
  8. 13. the combustion reaction releases _______ energy