Summary transition elements and redox chemistry notes

Transition elements
OCR-A LEVEL CHEMISTRY
MODULE 5



d-block elements that form at least 1 ion with a partially filled d-orbital

1) Sc forms only Sc ³+

Sc³+: 1s² , 2s², 2p⁶ , 3s² , 3p⁶

Sc³+ has empty d-orbitals = NOT a transition element by definition

2) Zn only forms Zn²+

Zn²+ : 1s² , 2s², 2p⁶ , 3s² , 3p⁶, 4s², 3d¹⁰

Zn²+ has fully filled d-orbitals = NOT a transition element by definition

But they’re still d-block elements

Properties

Due to incomplete d-orbitals :

● Conductors of heat and electricity

● Shiny, stronger and harder than group 2 metals

● High melting and boiling points

Variable oxidation states

Number of oxidation states increases across the period up to Mn, then decreases

All transition metals form compounds with an oxidation number of 2

Each oxidation state has a characteristic colour



1

, The higher the oxidation state, the stronger the oxidising agent

Uses as catalysts

Outer shell electrons (highest energy) are easily lost or gained

The oxidation state fluctuates as electrons are accepted or donated

This increases the speed of electron transfer

+ Reduces energy usage (used at lower temperatures)

- Toxic transition elements

Eg. Cu = liver damage

Mn = physical tremors




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