205 Chemistry Notes 2


Published on

Periodic Table Group Properties

Published in: Education, Business, Technology
1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

205 Chemistry Notes 2

  1. 1. Chapter 16 Group Properties
  2. 2. <ul><li>1 outer shell electron </li></ul><ul><li>form ions with a charge of +1; form ionic compounds of similar formulas </li></ul><ul><li>very reactive metals; metals are kept under oil to prevent corrosion by air and water </li></ul><ul><li>shiny, silvery solids </li></ul><ul><li>soft and have low densities (can be cut with a knife!) </li></ul><ul><li>low melting points </li></ul><ul><li>react with water to give alkaline solutions, producing metal hydroxide and hydrogen gas </li></ul>group I elements - the alkali metals properties
  3. 3. changes down group I elements <ul><li>densities increase </li></ul><ul><li>melting points decrease </li></ul><ul><li>more reactive </li></ul>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 1.9 Density (g/cm 3 ) 29 Cs caesium Melting Point ( ° C) Symbol Name
  4. 4. <ul><li>reactions of group I elements with water: </li></ul>reaction with water group I elements - the alkali metals 2K + 2H 2 O 2KOH + H 2 explosion potassium 2Na + 2H 2 O 2NaOH + H 2 very fast reaction; sometimes sodium catches fire and explodes sodium 2Li + 2H 2 O 2LiOH + H 2 fast reaction lithium Equation for Reaction Observation Alkali Metals
  5. 5. group VII elements - the halogens <ul><li>7 outer shell electrons </li></ul><ul><li>ions with a charge of -1 </li></ul><ul><li>very reactive non-metals </li></ul><ul><li>diatomic molecules </li></ul><ul><li>low melting and boiling points </li></ul><ul><li>a more reactive halogen will displace a less reactive halogen from an aqueous solution of its ions </li></ul>C l 2 (aq) + 2KI (aq) I 2 (aq) + 2KC l (aq) properties <ul><li>react vigorously with metals to form ionic salts </li></ul>2Na (s) + C l 2 (g) 2NaC l (s)
  6. 6. changes down group VII elements <ul><li>melting and boiling points increase </li></ul><ul><li>elements become darker in colour </li></ul><ul><li>less reactive </li></ul><ul><li>change from gas to solid </li></ul>changes in physical properties of group VII elements gaseous chlorine liquid bromine solid iodine group VII elements - the halogens
  7. 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. 8. group 0 elements – the noble gases <ul><li>monatomic, colourless gases </li></ul><ul><li>full valence shells; no wish to form bonds with other atoms </li></ul><ul><li>unreactive </li></ul><ul><li>low melting and boiling points </li></ul>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. 9. the transition elements properties <ul><li>high densities and melting points </li></ul><ul><li>not very reactive </li></ul><ul><li>strong and hard metals </li></ul><ul><li>variable valency and oxidation states in compounds </li></ul>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. 10. the transition elements properties <ul><li>coloured compounds formed; solutions of ions in water are also coloured </li></ul><ul><li>elements and their compounds are good catalysts </li></ul>solutions of transition metal ions from left: manganate(VII), dichromate(VI), copper(II), nickel(II)
  11. 11. the transition elements <ul><li>uses of transition elements and their compounds: </li></ul>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. 12. halogens group properties alkali metals noble gases <ul><li>atoms have 1 outer shell electron </li></ul><ul><li>form M + ions </li></ul><ul><li>conduct electricity </li></ul><ul><li>have low melting points </li></ul><ul><li>are soft </li></ul><ul><li>have low densities </li></ul><ul><li>very reactive metals </li></ul><ul><li>react with water to form alkali MOH and H 2 gas </li></ul>transition elements <ul><li>conduct electricity </li></ul><ul><li>have high melting and boiling points </li></ul><ul><li>have high densities </li></ul><ul><li>have variable valency </li></ul><ul><li>form coloured compounds </li></ul><ul><li>are often good catalysts </li></ul><ul><li>form strong alloys </li></ul><ul><li>atoms have 8 outer shell </li></ul><ul><li>electrons </li></ul><ul><li>unreactive gases </li></ul><ul><li>form monatomic molecules </li></ul><ul><li>atoms have 7 outer shell electrons </li></ul><ul><li>form X - ions </li></ul><ul><li>do not conduct electricity </li></ul><ul><li>have low melting and boiling points </li></ul><ul><li>form diatomic molecules X 2 </li></ul><ul><li>reactive non-metals </li></ul><ul><li>form salts with metals </li></ul><ul><li>each displaces other halogens below </li></ul><ul><li>from their salts in water </li></ul>properties changes down the group <ul><li>more reactive </li></ul><ul><li>melting point decreases </li></ul><ul><li>density increases </li></ul>properties properties changes down the group <ul><li>more dense </li></ul>properties changes down the group <ul><li>darker in colour </li></ul><ul><li>melting and boiling </li></ul><ul><li>points increase </li></ul><ul><li>from gas to solid </li></ul><ul><li>less reactive </li></ul>of of of of