Chemistry crossword

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Across
  1. 3. combination of pure substances; unlike acompound, the components of a mixture do not combine chemically and are not always in the same ratio
  2. 5. vertical column of elements in the periodic table; of elements in a family all have similar chemical properties; also called a family
  3. 8. positively charged centre of an atom contains protons and neutrons
  4. 9. change from liquid to soild
  5. 11. an experiment in which one or more products of a chemical reaction can escape
  6. 15. elements and compounds that organisms need for living, growing, and reproducing
  7. 18. compound made up of units calledamino acids; protein molecules contain atoms ofnitrogen, hydrogen, oxygen, and carbon
  8. 19. substance that helps a chemical reaction to proceed
  9. 24. group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals
  10. 25. group 18 elements in the periodic table;the most stable and unreactive elements
Down
  1. 1. amount of mass in a given voilume of a substance
  2. 2. that describes a particularsubstance (e.g., colour, lustre, melting point,crystal shape, solubility, density)
  3. 4. atom that has become electrically charged because it has lost or gained electrons; a positiveion is an atom that has lost one or more electrons;a negative ion is an atom that has gained one ormore electrons
  4. 6. new substance produced in a chemical reactants between reactents
  5. 7. catalyst involved in a chemical reaction in living things
  6. 10. substance that reacts with another substance or substances in a chemical reaction to create new substances with different propertier
  7. 12. homogeneous mixture; mixture of two or more pure substances that looks like one substance
  8. 13. mass of a substance that can dissolve in a given amount of solvent to form a saturated solution at a given temperature
  9. 14. positively charged particle in the nucleus of an atom
  10. 16. substance made of only one kind of matter, which has a unique set of properties
  11. 17. group 17 elements in the periodic table;the most reactive non-metals
  12. 20. number of protons in the nucleus of one atoms
  13. 21. (SO2(g))forms when sulfur combines swith oxygen in the air; major air pollutant that forms both smog and acid rain; major source:industrial processes
  14. 22. chemistry) vertical column of elements in the periodic table; elements in a family all have similar chemical properties; also called a group
  15. 23. group of atoms joined by covalent bond