chemistry

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Across
  1. 3. a method of seperating substances of various sizes using a sieve
  2. 6. , molecules of compound can be broken down into their elements by a ___________________ only
  3. 7. , exists as solid
  4. 11. , contains penicillin and tetracylin
  5. 16. , sodium,chloride
  6. 17. , Mendeleev listed the ______ known elements and their properties on cards
  7. 18. , they include harmful and toxic chemicals , suspended wastes and heavy metals .these make the soil unfit to grow crops and are very harmful to animals .
  8. 20. , The number of protons in the nucleus of an atom
  9. 21. atomic no of sulphur
  10. 24. he is the symbol of ____
  11. 25. , __ litre of water is used to produce one sheet of paper
  12. 27. , when is world water day celebrated ?
  13. 29. , _____ is a branch of science that deals with the study of composition properties and structure of substances .
  14. 31. symbol of magnesium
  15. 33. , a molecule of water can be broken down into hydrogen and oxygen by the process of electrolysis
  16. 36. , the iron pillar of Qutub Minar is ______ and has not corroded because it is alloy made up of high quality of iron .
  17. 38. , exists as liquid
  18. 39. , carbon,oxygen
  19. 41. , latin name of iron
Down
  1. 1. , atomic number of oxygen
  2. 2. , first synthetic fibre
  3. 4. - also called semi-metals
  4. 5. , a solution is formed when a solute is _______ in water
  5. 8. , used to cutdown friction
  6. 9. , core of the pencil is made up of a non toxic mineral called _____ .
  7. 10. , latin name of potassium
  8. 12. , water in rivers and oceans provides a surface for ________ and shipping
  9. 13. - helium,neon,argon,krypton,redon,xenon
  10. 14. , ___ is a complex substance made up of pigments, resins , dyes and other particulate material
  11. 15. atomic number of neon
  12. 19. , heavier solids settle down at the bottom when mixture is left undisturbed for a while .
  13. 22. , expansion of matter
  14. 23. - full form of PET
  15. 26. , atomic number of sodium
  16. 28. , solids cannot be ______ because their molecules are closely packed and have negligible intermolecular spaces
  17. 30. process by which we seperate sand and water
  18. 31. ,___ which has chemicals like magnesium , silicon and oxygen
  19. 32. , symbol of iron
  20. 34. , fibres made from from chemical polymers in a laboratory
  21. 35. , atomic number of calcium
  22. 37. , symbol of plumbum
  23. 40. , smallest unit of matter