Thanks to Doc Brown of Chem Help. Net for these great chemistry revision notes. Check out his site for more! (a) High Melting Point and Boiling Point The bonding between the atoms in transition metals is very strong. The strong attractive force between the atoms is only weakened at high temperatures, hence the high melting points and boiling points.
For example: iron melts at 1535 C and boils at 2750 C BUT a Group 1 Alkali Metals such as sodium melts at 98 C and boils at 883 C. (b) High density Another consequence of the strong bonding between the atoms in transition metals is they are tightly held together to give a high density. For example: iron has a density of 7. 9 g / cm 3 and sodium has a density of 0. 97 g / cm 3 (and floats on water while fizzing! water has a density of 1. 0 g / cm 3).
(c) Form coloured compounds and ions in solution Transition metals tend to form more coloured compounds more than other elements either in solid form or dissolved in a solvent. The colours of some transition metal salts in aqueous solution are shown below 10 Sc – scandium salts such as the chloride, S cCl 3, are colourless and not typical of transition metals Ti – titanium (III) chloride, Till 3, is purple V – vanadium (III) chloride, VCl 3, is green Cr – chromium (III) sulphate, Cr 2 (SO 4) 3, is dark green Mn – potassium manganate (VII), Mno 4, is purple Fe – iron (III) chloride, Feel 3, is yellow-orange-brown Co – cobalt sulphate, CoSO 4, is pinkish Ni – nickel chloride, Nice 2, is green Cu – copper (II) sulphate, Cu SO 4, is deep blue Zn – zinc salts such as zinc sulphate, Zn SO 4, are usually colourless and not typical of transition metals (d) Catalytic Properties (1 The metallic elements themselves Many transition metals are used directly as catalysts in industrial chemical processes and in the anti-pollution catalytic converters in car exhausts. For example iron is used in the Haber Synthesis of ammonia: Nitrogen + Hydrogen Ammonia or N 2 + 3 H 2 2 NH 3 via the Fe catalyst atoms (2) The compounds of transition metals As well as the metals, the compounds of transition metals also acts as catalysts. For example manganese dioxide (or manganese (IV) oxide), MnO 2, a black powder, readily decomposes an aqueous solution of hydrogen peroxide: Hydrogen peroxide water + oxygen or 2 H 2 O 2 2 H 2 O + O 2 via MnO 2 as the catalyst.
The Essay on Types of transitions
Types of transition table. Types of transition Description of the transition Explain (how to give adult support for each transition) Physical transition A physical transition is something that every child goes through in their life, for example “Children attending a setting for the first time” (Walker, 2012, p44). You could support a child going through this transition by staying with the child at ...
