Across
- 1. A silvery-white metal, is malleable, somewhat ductile, and has a highly crystalline structure.
- 4. Forms an unstable hydrate. In a vacuum discharge tube, glows reddish orange.
- 5. Is not particularly toxic and is an essential element in the growth of all animals and plants.
- 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.
- 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.
- 12. The only liquid nonmetallic element. It is a member of the halogen group.
- 13. It tarnishes in air, and when heated rapidly oxidises and has a garlic odour.
- 14. A greenish yellow gas which combines directly with nearly all elements. The gas irritates the mucous membranes and the liquid burns the skin.
- 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.
- 19. Found as a constituent in most meteorites,a silvery white metal that takes on a high polish. It is hard, malleable and ductile.
- 20. An unreactive, colourless, and odourless monoatomic gas,second most abundant element in the universe.
- 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.
- 22. Is a pale yellow, odourless, brittle solid, which is insoluble in water but soluble in carbon disulphide & is essential to life.
- 24. The most electronegative and reactive of all elements.
- 25. It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm.
- 26. The only common metal liquid at ordinary temperatures, is sometimes called quicksilver.
- 28. It exhibits luminescence, as do its salts; it decomposes in water and is somewhat more volatile than barium.
- 29. Is a Group 16 element. About one fifth of the atmosphere is this gas
- 30. It makes a good atmosphere for working with air-sensitive materials since it is heavier than air and less reactive than N2.
Down
- 2. Is the key component of haemoglobin.
- 3. Element that has properties which are borderline between metals and non-metals (semimetallic).
- 6. Is a Group 15 element. Makes up about 78% of the atmosphere by volume
- 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.
- 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.
- 11. Is of great interest because of its application to nuclear power and nuclear weapons.
- 15. Is present in the sun and stars and is a principal component of a class of meteorites known as aerolites.
- 16. An alkali metal containing just a single valence electron.
- 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.
- 23. Is reddish with a bright metallic lustre. It is malleable, ductile, and a good conductor of heat and electricity.
- 27. Found free in nature in three allotropic forms: amorphous, graphite, and diamond.