Transition elements
| English | Chinese | Pinyin |
|---|---|---|
| transition element | 过渡元素 | guò dù yuán sù |
| d-block | d区 | d qū |
| oxidation state | 氧化态 | yǎng huà tài |
| catalyst | 催化剂 | cuī huà jì |
| complex ion | 配离子 | pèi lí zi |
The colourful middle block
- A transition element 过渡元素 is a d-block d区 element that forms one or more stable ions with incomplete d orbitals.
- Scandium and zinc are d-block but not transition (their stable ions have empty or full d orbitals).
- Transition metals share four special properties.
Transition element property lab
Sort transition-metal evidence by the property it shows.
A transition element is a d-block element that:
The incomplete d orbitals (in a stable ion) define a transition element.
Why are scandium and zinc not classed as transition elements?
Sc³⁺ has an empty d sub-shell and Zn²⁺ a full one, so neither has incomplete d orbitals in its stable ion.
A transition element forms at least one ion with an incomplete ______ subshell.
This gives variable oxidation states and colour.
Four key properties (and why)
| Property | Reason |
|---|---|
| variable oxidation state 氧化态 | the 3d and 4s sub-shells are close in energy |
| act as a catalyst 催化剂 | more than one oxidation state, plus vacant d orbitals |
| form complex ions 配离子 | vacant d orbitals accept lone pairs |
| form coloured compounds | electrons move between split d orbitals |
Six transition-metal solutions, each a different colour: cobalt(II) (red), dichromate (orange), chromate (yellow), nickel(II) (green), copper(II) (blue) and permanganate (violet)
Transition metals show variable oxidation states because:
Similar energies mean similar small amounts of energy can remove different numbers of electrons.
Transition metal compounds are coloured because:
Ligands split the d orbitals; absorbing light of the gap energy gives the colour we see.
Match each transition-element fact.
Each item links the term to its correct meaning.
Why transition metals are special
- They form coloured compounds, act as catalysts, and show variable oxidation states.
- All come from the partly filled d subshell.
A ruby is red because of transition-metal (chromium) ions held in its lattice.
Scandium and zinc are exceptions
- Scandium and zinc are d-block but not classed as transition metals.
- Their ions do not have a partly filled d subshell, so they lack the typical properties.
The four key properties of the transition elements
You've got it
- a transition element forms stable ions with incomplete d orbitals (not Sc or Zn)
- four properties: variable oxidation state (3d/4s close), catalysis, complex ions (accept lone pairs), colour (split d orbitals)