State three characteristic properties of transition metals

Here are three characteristic properties of transition metals:

1. Variable Oxidation States: Transition metals can lose different numbers of electrons, forming ions with various positive charges (oxidation states). For example, iron can exist as Fe²⁺ or Fe³⁺.

2. Formation of Coloured Compounds: Many compounds formed by transition metals are coloured. This is due to the d-electrons absorbing certain wavelengths of visible light when transitioning between energy levels.

3. Catalytic Activity: Transition metals and their compounds often act as effective catalysts. They can speed up chemical reactions without being consumed themselves, often by providing an alternative reaction pathway with lower activation energy.