Alkali & transition metals

• ALKALI METALS

  The group 1 elements, which are highly REACTIVE and are SOFT metals with low density and all has ONE ELECTRON in their OUTER SHELL.

  
• Reactivity of Alkali Metals

  reactivity INCREASES as you go down the group, because there are more shells, so there's less attraction between the nucleus and the outer shell, so the atom loses an electrons more easily.

  
• Reactivity of Alkali Metals

  Has LOWER MELTING AND BOILING POINTS and a HIGHER RELATIVE ATOMIC MASS as you move down the group.
• Reactivity of Alkali Metals

  When reacting, group 1 elements form IONIC COMPOUNDS with non-metals, resulting in white solids that dissolve in water to create colourless ALKALI solutions.
• How does the size of a potassium atom compare with the size of a sodium atom?

  potassium is large because it has more shell.
• Explain why sodium is less reactive than potassium.

  Sodium has fewer shells and the outer shell is close to nucleus, so there's greater attraction between nucleus and outer shell, so more energy needed to remove an electron.
• When sodium reacts with water it:

  • melts and form a ball
  • floats (because it has a lower density than water)
  • moves
  • bubbles
  • fizzing
  • gets smaller / disappears / dissolves

  produces:

  • gas
  • steam
  • mist
  • Vapour

  
• When potassium reacts with water it:

  1. melts and form a ball
  2. floats (because it has a lower density than water)
  3. moves faster
  4. bubbles faster
  5. disappears faster
  6. catches fire
  7. lilac flame
  8. explodes

  
• when lithium reacts with water it:

  • melts into a ball
  • floats (because it has a lower density than water)
  • bubbles

  
• Transition metals form coloured compounds:

  • Gold (Au) is gold
  • Iron (Fe) is silvery-grey.

  alkali metals are just grey.
• Transition metals have different oxidation states

  • Fe2+ = brown
  • Fe3+ = green
• differences between alkali and transition metals have:

  • higher melting points
  • higher densities
  • greater strength
  • greater hardness
  • less reactive
  • Has different oxidising states
  • Forms coloured compounds
  • can be used as a catalyst
• transition metal properties that they share with other metals:

  • conduct electricity in solid and liquid state
  • shiny when freshly cut
• As the melting point decreases down group 1, the atomic number increases down the group.
• Alkali metals with water: (X = ANY ALKALI METAL)

  Reacts VIGOROUSLY to produces Hydrogen gas and metal hydroxides (alkaline when dissolves in water and it's soluble in water, so it has a pH of 13 - 14).

  • The reactions become MORE VIOLENT reactions FURTHER DOWN the group.  

  Word equation:

  • metal + water -> Metal hydroxide + hydrogen

  Symbol equation:

  • 2X(s) + 2H2O(l) -> 2XOH(aq) + H2(g)
• Alkali metals reacting with chlorine: (X IS ANY ALKALI METAL)


  Reacts with Chlorine to form METAL CHLORIDES, which are WHITE SALTS.

  • The reactions become more VIGOROUS down the group.

  Word Equation:

  • Metal + Chlorine -> Metal Chloride

  Symbol Equation:

  • 2X(s) + Cl2(g) -> 2XCl(s)
• alkali metals reacting with oxygen: (X IS ANY ALKALI METAL)


  In the air, it forms METAL OXIDES (this is why alkali metals rust when exposed to air) and is covered in a dull coating.

  Word Equation:

  • Metal + Oxygen -> Metal Oxide

  Symbol Equation:

  • 4X(s) + O2(g) -> 2X2O(s)
• Word Equation:

  • Francium + Phosphorus -> francium phosphide


  Symbol Equation:

  • 3Fr + P -> Fr3P
• Hot sodium is put in a gas jar of chlorine.


  the observations:

  • yellow gas
  • yellow flame
  • white solid
  • Disappears
  • Dissolves
  • Colour of gas / chlorine
• transition metals


  They have no group, they are between group 2 and 3 and are found in the middle of the periodic table.

  • Can be used as catalysts to speed up chemical reactions.
  • They have different / variable oxidation states, (which causes the colour of the compound) while alkali has state of +1 charge.
• Metals have delocalised electrons that carry charge to help conduct electricity.
• Properties of transition metals:

  • High melting / boiling points
  • High densities
  • malleable
  • ductile
  • strong (not brittle)
  • has different oxidisation states
  • forms coloured compounds
  • can be used as a catalyst
  • hard (inflexible)
  • not very reactive
  • good conductors of heat and electricity
• • The catalyst used in the Haber process for making ammonia is iron.
  • The catalyst used in the hydrogenation of alkenes is nickel.

  
• Effects of atmospheric pollution, which are reduced by using catalytic converters:

  • Acid rain
  • Respiratory problems
  • carbon monoxide
  • smog / global dimming