Periodic Table Grp Properties

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Notes from Sec 2! :)

Transcript of Periodic Table Grp Properties

  • 1. Chapter16 Group Properties

2.

  • 1 outer shell electron
  • form ions with a charge of +1; form ionic compounds of similar formulas
  • very reactive metals; metals are kept under oil to prevent corrosion by air and water
  • shiny, silvery solids
  • soft and have low densities (can be cut with a knife!)
  • low melting points
  • react with water to give alkaline solutions, producing metal hydroxide and hydrogen gas

group I elements - the alkali metals properties 3. changes down group I elements

  • densities increase
  • melting points decrease
  • more reactive

group I elements - the alkali metals 39 1.5 Rb rubidium 64 0.86 K potassium 98 0.97 Na sodium 180 0.53 Li lithium 1.9Density (g/cm 3 ) 29 Cs caesium Melting Point ( C) Symbol Name 4.

  • reactions of group I elements with water:

reaction with water group I elements - the alkali metals 2K + 2H 2 O2KOH + H 2 explosion potassium 2Na + 2H 2 O2NaOH + H 2 very fast reaction; sometimes sodium catches fire and explodes sodium 2Li + 2H 2 O2LiOH + H 2 fast reaction lithium Equation for Reaction Observation Alkali Metals 5. group VII elements - the halogens

  • 7 outer shell electrons
  • ions with a charge of -1
  • very reactive non-metals
  • diatomic molecules
  • low melting and boiling points
  • a more reactive halogen will displace a less reactive halogen from an aqueous solution of its ions

C l 2 (aq)+ 2KI (aq) I 2 (aq)+ 2KC l (aq) properties

  • react vigorously with metals to form ionic salts

2Na (s)+ C l 2 (g) 2NaC l (s) 6. changes down group VII elements

  • melting and boiling points increase
  • elements become darker in colour
  • less reactive
  • change from gas to solid

changes in physical properties of group VII elements gaseous chlorine liquid bromine solid iodine group VII elements - the halogens 7. group VII elements - the halogens pale yellow gas -188 -220 F2 fluorine 114 -7 -101 Melting Point ( C) 184 59 -35 Boiling Point ( C) solid liquid gas Physical State at Room Condition black I 2 iodine Reddish brown Br 2 bromine yellow-green C l 2 chlorine Colour Formula of Molecule Halogens 8. group 0 elements the noble gases

  • monatomic, colourless gases
  • full valence shells; no wish to form bonds with other atoms
  • unreactive
  • low melting and boiling points

properties provide an inert atmosphere unreactive; hot wire will not burn in the gas very low density; unreactive Properties light bulbs and steel production argon advertising strip lights neon balloons and modern airships helium Uses Noble Gases 9. the transition elements properties

  • high densities and melting points
  • not very reactive
  • strong and hard metals
  • variable valency and oxidation states in compounds

8.9 8.9 7.9 7.2 Density (g/cm 3 ) 1083 1453 1535 1890 Melting Point ( C) Other Metals Transition Metals 850 1.5 calcium copper 660 2.7 aluminium nickel 650 1.7 magnesium iron 98 0.97 sodium chromium Density (g/cm 3 ) Melting Point ( C) Metal Metal 10. the transition elements properties

  • coloured compounds formed; solutions of ions in water are also coloured
  • elements and their compounds are good catalysts

solutions of transition metal ions from left: manganate(VII), dichromate(VI), copper(II), nickel(II) 11. the transition elements

  • uses of transition elements and their compounds:

as a catalyst in Haber Process for the manufacturing of ammonia iron bright colours in porcelain copper, iron and cobalt filaments for light bulbs tungsten as a catalyst to manufacture margarine from vegetable oils nickel as a catalyst in Contact Process for the manufacturing of sulphuric acid vanadium(V) oxide nails, ships iron mixed with a little carbon (alloy steel) Uses Transition Elements/ Compounds 12. halogens group properties alkali metals noble gases

  • atoms have 1 outer shell electron
  • form M +ions
  • conduct electricity
  • have low melting points
  • are soft
  • have low densities
  • very reactive metals
  • react with water to form alkali MOH and H 2gas

transition elements

  • conduct electricity
  • have high melting and boiling points
  • have high densities
  • have variable valency
  • form coloured compounds
  • are often good catalysts
  • form strong alloys
  • atoms have 8 outer shell
  • electrons
  • unreactive gases
  • form monatomic molecules
  • atoms have 7 outer shell electrons
  • form X -ions
  • do not conduct electricity
  • have low melting and boiling points
  • form diatomic molecules X 2
  • reactive non-metals
  • form salts with metals
  • each displaces other halogens below
  • from their salts in water

properties changes down the group

  • more reactive
  • melting point decreases
  • density increases

properties properties changes down the group

  • more dense

properties changes down the group

  • darker in colour
  • melting and boiling
  • points increase
  • from gas to solid
  • less reactive

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