This definitions covers Key Definitions within Transition Metals (HT) for GCSE Chemistry. Revise Transition Metals (HT) in Atomic Structure for GCSE Chemistry with 20 exam-style questions and 20 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 6 of 11 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 6 of 11
Practice
20 questions
Recall
20 flashcards
📖 Key Definitions
Transition metals: The block of metals in the centre of the periodic table (d-block), between Groups 2 and 3. They have typical metal properties (hard, dense, high melting point) and form coloured compounds, variable ions, and catalysts.
Catalyst: A substance that speeds up a chemical reaction without being used up or chemically changed at the end of the reaction. Transition metals are effective catalysts due to their ability to change oxidation state.
Variable oxidation state: The ability of transition metal ions to exist with different charges, e.g., iron can form Fe²⁺ or Fe³⁺. This is unlike Group 1 metals, which only form +1 ions.
Alloy: A mixture of a metal with one or more other elements (usually metals or carbon). Transition metals form important alloys — steel (iron + carbon), brass (copper + zinc), bronze (copper + tin).