transition elements Flashcards
define a transition element
d block elements that can form stable ion(s) with unpaired electrons in the d orbital
describe the properties of TMs
form complexes
form coloured ions in solution
variable oxidation states
good catalysts
high density and mtp
why do TMs have variable oxidation states?
4s and 3d orbitals are very close in energy levels
what elements have exceptions in electronic configuration?
copper and chromium
Cu: [Ar] 4s^1 3d^5
Cr: [Ar] 4s^1 3d^10
give an example of a TM displayng catalytic behaviour
what are TM complexes?
central metal ion surrounded by ligands
what is a ligand?
a molecule/ion with a lone pair which can form a coordinate bond with the central metal ion
what is a bidentate ligand?
forms two coordinate bonds/takes two bites of the molecule
what is a coordination number?
number of coordinate bonds formed with central metal ion
why do TMs form coloured ions?
absorption and reflection of light
d orbital is split and some electrons become in an ‘excited state’ and the difference in energy of these states corresponds to a specific frequency/wavelength
why are some TM ions colourless?
what types of isomerism do complex ions show?
cis/trans
optical
