Transition Metals: Basics Flashcards
In which block are transition metals found?
The d-block.
In the first row of the d-block, which subshells contain the highest energy electrons?
4s and 3d.
What is the definition of a transition metal?
A transition metal is one that can form one or more stable ions with a partially filled d-subshell.
Which subshell is filled first, 4s or 3d? Also, are there any exceptions?
4s. Yes, Chromium and Copper.
Why is Sc not a transition metal?
It can only form one ion: Sc3+. This has an empty d-subshell.
Why is Zn not a transition metal?
It can only form one ion: Zn2+. This has a full d-subshell because the electrons are lost from the 4s subshell.
What’s special about the electronic configurations in Chromium and Copper that give them more stability?
Chromium has one electron in each orbital of the 3d subshell and just one in the 4s subshell.
Copper has a full 3d subshell and just one electron in the 4s subshell.
When positive ions are formed from transition metals, which subshell loses its electrons first?
The 4s subshell.
What evidence does the first I.E. provide about the electronic configurations of the transition elements?
Roughly the same from Sc to Cu. Implies a similar electronic structure, and that the first electron is lost from the same shell (4s).
What evidence does the second I.E. provide about the electronic configurations of the transition elements?
Steady increase across the elements. Cr and Cu are slightly higher than expected because the second electron is taken from much nearer the nucleus (3d), so more energy required to remove it.
What evidence does the third I.E. provide about the electronic configurations of the transition elements?
Steady increase across the elements. Step down at iron though, because from Fe onwards, the 3rd electron removed comes from a paired 3d orbital. The paired electrons repel each other, so easier to remove one.
What 4 special chemical properties can occur in transition metals?
- Can form complex ions.
- Can form coloured ions in solution.
- Can act as good catalyst.
- Can exist in variable oxidation states.
