Transition Metals Flashcards
What is a transition metal?
A metal that can form one or more stable ions with an incomplete sub-shell.
Write the electronic configuration of Ti, V, Cr, Mn, Fe, Co, Ni and Cu?
How are electrons lost from trasition metal atoms to form ions?
Electrons are lost from the 4s subshell first as the 4s subshell is higher in energy.
Write the electronic configuration of Fe 2+, Fe 3+ and Mn 2+ ions.
Why is scandium not a transition metal?
It can only form one stable ion Sc 3+ and it does not have an incomplete sub-shell.
Why is zinc not a transition metal?
It can only form one stable ion Zn 2+ and it does not have an incomplete sub-shell.
What are the physical properties of transition metals?
They have a high density. They have high melting and boiling points.
What are the chemical properties of transition metals?
- They can form complex ions.
- They form coloured ions.
- They are good catalysts.
- They have varying oxidation states.
What is a complex ion?
A metal ion is coordinately bonded to many ligands.
What is a ligand?
An atom, ion or molecule that can donate a pair of electrons.
What are monodentate ligands?
Ligands that can donate only one pair of electrons and form one coordinate bond with the central metal ion.
What are examples of monodentate ligands?
Ammonia. water and chloride ions.
What are bidentate ligands?
Ligands that can donate two pairs of electrons and form two coordinate bonds with the central metal ion.
What are examples of bidentate ligands?
ethane-1,2-diamine
What are multidentate ligands?
Ligands that can donate more than two pairs of electrons and form more than two coordinate bonds with the central metal ion.
What are examples of multidentate ligands?
EDTA 4- forms 6 coordinate bonds.
What shape are the complex ions when there are 6 coordinate bonds?
octahedral
What shape are the complex ions when there are 6 coordinate bonds?
- Tetrahedral.
- Square planar.
What are stereoisomers?
Compounds that have the same molecular formula but a different arrangement of atoms within a space.
What are optical isomers?
Isomers that are mirror images of each other and are non-superimposable.
Where does optical isomerism happen in complex ions?
When three bidentate ligands bind to the central metal ion.
Where does E-Z isomerism happen in complex ions?
- When 4 monodentate ligands bind to the central metal ion.
- Octahedral complex ions that 4 of the same ligands and 2 different ligands bound to the central metal ion.
What is the structure of cisplatin?
How do different energy levels form in the 3d-subshell?
When the ligands bond to the ions some orbitals gain more energy than others and that splits the subshell into different energy levels.
How do electrons jump up energy levels?
They need to absorb energy equal to the energy gap which they get from visible light.
Why do transition metals form coloured compounds?
When visible light hits a transition metal ion some frequencies are absorbed so the electrons can jump up an energy level. The rest of the frequencies are reflected and combined to make the complementary colour of the absorbed frequencies.
Why are some compounds colourless?
They have no 3d electrons or their 3d subshell is full meaning that no electrons will jump up an energy level and no energy will be absorbed. Since all frequencies of light are reflected the compound appears white or colourless.
What can cause a change in colour in a transition metal?
- Change in oxidation state.
- Change in coordination number.
- Change in ligand.