Transition Elements (no colours) OCR GCE Chemistry A Level

Why do OCR not classify Sc and Zn as transition elements?

• They each have an incomplete d-subshell

• They each have a complete d-subshell

• They each form at least one ion with a complete d-subshell

• Neither forms an ion with an incomplete d-subshell

Answer explanation

There are arguments between chemists over TM classification, but this is what OCR expects

With spaces between the subshells, write the full electron configuration of Fe

Answer explanation

Make sure you know why it must be 3d6 (count across from Sc)

With spaces between the subshells, write the full electron configuration of Fe³⁺

Answer explanation

1) Write out the elec config of the atom

2) Remove the 4s electrons first

3) Then remove 3d electrons until you've removed enough

With spaces between the subshells, write the full electron configuration of Cu

Answer explanation

Copper and Chromium don't follow the usual filling order.

Steps:

1) Write out the elec config of the atom following the usual order

2) Promote one electron from 4s to 3d

(This gives a full d-subshell for Cu, and a half-full d-subshell for Cr. These configurations are particularly stable)

With spaces between the subshells, write the full electron configuration of Cu²⁺

Answer explanation

For ions:

1) Write the elec config of the atom

2) Remove electrons from 4s first

3) Then remove them from 3d until you've removed the right number

OCR expect you to learn examples for two different TMs for what?

• Reactive metals

• Compounds with the TM in different oxidation states

• Catalytic behaviour in industry

• Catalytic behaviour in laboratories

• Different coloured ions

A ligand exhibits coordinate bonding to a metal or metal _____ ?

A ligand that forms one coordinate bond is a __________ ligand

A ligand that forms three coordinate bonds is a __________ ligand

EDTA is a ____dentate ligand