Periodic Table

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Across
  1. 1. A silvery-white metal, is malleable, somewhat ductile, and has a highly crystalline structure.
  2. 4. Forms an unstable hydrate. In a vacuum discharge tube, glows reddish orange.
  3. 5. Is not particularly toxic and is an essential element in the growth of all animals and plants.
  4. 8. Characteristically a metallic yellow colour, It is metallic, with a yellow colour when in a mass, but when finely divided it may be black, ruby, or purple.
  5. 10. The metal has a low density, good strength, is easily fabricated, and has excellent corrosion resistance. The metal burns in air and is the only element that burns in nitrogen.
  6. 12. The only liquid nonmetallic element. It is a member of the halogen group.
  7. 13. It tarnishes in air, and when heated rapidly oxidises and has a garlic odour.
  8. 14. A greenish yellow gas which combines directly with nearly all elements. The gas irritates the mucous membranes and the liquid burns the skin.
  9. 17. A grayish-white, fairly tough metal. Is the eighth most abundant element in the earth's crust although not found in it's elemental form. It is a Group 2 element.
  10. 19. Found as a constituent in most meteorites,a silvery white metal that takes on a high polish. It is hard, malleable and ductile.
  11. 20. An unreactive, colourless, and odourless monoatomic gas,second most abundant element in the universe.
  12. 21. Seventh most abundant and makes up about 1.5 by weight of the earth's crust. Is an essential constituent for plant growth and it is found in most soils.
  13. 22. Is a pale yellow, odourless, brittle solid, which is insoluble in water but soluble in carbon disulphide & is essential to life.
  14. 24. The most electronegative and reactive of all elements.
  15. 25. It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm.
  16. 26. The only common metal liquid at ordinary temperatures, is sometimes called quicksilver.
  17. 28. It exhibits luminescence, as do its salts; it decomposes in water and is somewhat more volatile than barium.
  18. 29. Is a Group 16 element. About one fifth of the atmosphere is this gas
  19. 30. It makes a good atmosphere for working with air-sensitive materials since it is heavier than air and less reactive than N2.
Down
  1. 2. Is the key component of haemoglobin.
  2. 3. Element that has properties which are borderline between metals and non-metals (semimetallic).
  3. 6. Is a Group 15 element. Makes up about 78% of the atmosphere by volume
  4. 7. It forms compounds with most elements, but is less reactive than the other halogens. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulphide to form beautiful purple solutions.
  5. 9. The lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight.
  6. 11. Is of great interest because of its application to nuclear power and nuclear weapons.
  7. 15. Is present in the sun and stars and is a principal component of a class of meteorites known as aerolites.
  8. 16. An alkali metal containing just a single valence electron.
  9. 18. A silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. It is somewhat decorative. It is easily formed, machined, and cast.
  10. 23. Is reddish with a bright metallic lustre. It is malleable, ductile, and a good conductor of heat and electricity.
  11. 27. Found free in nature in three allotropic forms: amorphous, graphite, and diamond.