Year 9 Elements

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Across
  1. 3. a type of substance that is made up of 2 or more atom types that are chemically joined together
  2. 5. this type of change is irreversible
  3. 7. the substance(s) that are produced in a chemical reaction
  4. 8. a subatomic particle that is found in the nucleus that has no charge
  5. 10. this is the horizontal row that tells us how many electron shells an atom has
  6. 15. a positive test for this gas is if a glowing split relights
  7. 16. a type of substance that is made up of 2 or more substances that are NOT chemically joined together
  8. 18. a positive test for this gas is if a lit splint makes a pop sound
  9. 19. this number tells us the number of protons PLUS the number of neutrons
  10. 20. a subatomic particle that is found in shells around the nucleus and has a negative charge
Down
  1. 1. this kind of change involves only a substance changing it's state
  2. 2. this number tells us only the number of protons (and therefore electrons as atoms are neutral overall)
  3. 4. a subatomic particle that is found in the nucleus and has a positive charge
  4. 6. a positive test for this gas is if limewater goes cloudy
  5. 9. a type of substance that is made up of only one atom type
  6. 11. this column tells us the number of electrons in the last shell of an atom
  7. 12. the number of electrons in the last shell of silicon
  8. 13. the substance(s) that go into a chemical reaction
  9. 14. the element found in group 1, period 4
  10. 17. the symbol used to show the direction of a chemical reaction