D block

• Os has the highest oxidation state
• Tungsten(W) has the highest melting point.
• Silver has the most conducting nature
• Technetium is the first man made metal
• Zinc cadmium and mercury are not Transition Elements because of there fully filled orbitals
• Transition metals have high melting and boiling points due to interatomic metallic bonding
• More interatomic interaction leads more enthalpy of atomisation
• steady decrease in the size with an increasing atomic number is called lanthanide contraction.
• incomplete filling of d-orbitals leads to the oxidation states differing from each other by unity.
• Calomel is Hg2C12 in which Hg oxidation state is +1
• Corrosive sublimate is HgCl2 in which Hg oxidation state is +2
• Cu2+ is more stable than cu+ in aqueous medium due to hydration Energy
• The ability of fluorine to stabilise the highest oxidation state is due to higher lattice energy or higher bond enthalpy.
• Fluorine is unstable in lower oxidation states. Eg vx2 x = cl or br or I
• The ability of oxygen

  to stabilise these high oxidation states exceeds that of fluorine.
• The ability of oxygen to form multiple bonds to metals explains its superiority.
• Thus the highest Mn fluoride is MnF4, whereas the highest oxide is Mn2O7
• 1. V2+


  viloet
• 1. vanadium


  contact process
• Interstitial compounds are those which are formed when small atoms like H. C or N are trapped inside the crystal lattices of metals.
• Bronze is an alloy of copper and tin
• German silver is an alloy of copper zinc and nickel
• Brass is an alloy of copper and Zn
• Stainless steel is an alloy of chromium and iron
• Habers process


  finely dived iron
• Ziegler natter


  ethene-polyethene
• Cr+3 is green in colour
• Cr+6 is orange in colour
• Mn+2 is pink in colour
• Fe+2 is pale blue/green in colour
• Fe+3 is brownish red in colour
• Mn+7 is purple in colour
• Fe+3 is brownish yellow in colour
• Transition element: An element which forms at least one stable ion with a partially full d-shell of electrons
• Blue vitrol


  Cuso4
• Znso4


  White vitrol
• There is an increase in ionisation enthalpy along each series of the transition elements from left to right due to an increase in nuclear charge
• The irregular trend in the first ionisation enthalpy of the metals of 3d series, though of little chemical significance, can be accounted for by considering that the removal of one electron alters the relative energies of 4s and 3d orbitals.
• Increasing atomic number means increasing nuclear charge so there is more attraction between nucleus and outer shell electrons
• The 3d electrons shield the 4s electrons from the increasing nuclear charge somewhat more effectively than the outer shell electrons can shield one another.


  Therefore, the atomic radii decrease less rapidly. Thus, ionization energies increase only slightly along the 3d series.