What Are Transition Metals?
The periodic table is divided into several regions, and one of the most distinctive is the block of elements in the middle — the transition metals. These elements occupy Groups 3 to 12 (the d-block) in periods 4 through 7, forming a bridge between the reactive metals on the left and the non-metals on the right.
A group of metallic elements found in the d-block of the periodic table (Groups 3–12), characterised by partially filled d-orbitals, variable oxidation states, coloured compounds, and catalytic properties.
Well-known transition metals include iron (Fe), copper (Cu), nickel (Ni), chromium (Cr), manganese (Mn), cobalt (Co), titanium (Ti), silver (Ag), and gold (Au). You interact with many of these every day — the iron in your blood, the copper in electrical wiring, and the gold in jewellery.
Zinc (Zn) is often listed alongside transition metals in the periodic table, but by the strict definition it is not a true transition metal — its d-orbitals are completely filled in both the neutral atom and in its Zn²⁺ ion, so it does not show the typical transition metal properties like variable oxidation states or coloured compounds. We will mention zinc where relevant, but keep this distinction in mind.
Think of the periodic table like a city map. The alkali metals on the left are a busy residential street, the non-metals on the right are the commercial district, and the transition metals in the middle are the industrial zone — packed with variety, colour, and usefulness.
Position in the Periodic Table
The transition metals are located in periods 4 to 7, between Groups 2 and 13. On most periodic tables, they appear as the wide central block of elements.
The first row of transition metals (Period 4) is the most commonly studied at MYP level and includes:
| Element | Symbol | Atomic Number |
|---|---|---|
| Scandium | Sc | 21 |
| Titanium | Ti | 22 |
| Vanadium | V | 23 |
| Chromium | Cr | 24 |
| Manganese | Mn | 25 |
| Iron | Fe | 26 |
| Cobalt | Co | 27 |
| Nickel | Ni | 28 |
| Copper | Cu | 29 |
| Zinc | Zn | 30 |
Zinc (Zn) appears at the end of this row on the periodic table, but it does not fully meet the definition of a transition metal. Its 3d orbitals are completely filled in the neutral zinc atom and in its Zn²⁺ ion — meaning it does not display variable oxidation states or coloured compounds in the way true transition metals do. It is included in the table above for completeness, but you should be aware of this distinction.
The key reason transition metals have unique properties is related to their electron arrangement — specifically, the presence of partially filled d-orbitals (inner electron subshells). Think of d-orbitals as inner 'shelves' that can hold up to 10 electrons. When these shelves are only partly filled, they give rise to all the fascinating properties we will explore in this subtopic.
12 more sections in this topic
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