Coloured complexes absorb radiation in the

Options

A. visible region
B. infrared region
C. U.V. region
D. far IR region

Answer

To solve the question "Coloured complexes absorb radiation in the...", we need to analyze the behavior of colored complexes in relation to electromagnetic radiation. Here’s a step-by-step solution:

### Step 1: Understanding Colored Complexes
Colored complexes are typically transition metal complexes that exhibit color due to the presence of partially filled d-orbitals. The color observed is a result of the absorption of specific wavelengths of light.

**Hint:** Remember that the color seen is complementary to the color absorbed.

### Step 2: Electromagnetic Radiation and Energy Levels
When light (electromagnetic radiation) hits these complexes, photons can be absorbed if their energy matches the energy difference between the lower energy d-orbitals and the higher energy d-orbitals. This process is known as electronic transition.

**Hint:** Think about how energy levels in atoms and ions work, especially in transition metals.

### Step 3: Identifying the Regions of Electromagnetic Spectrum
The electromagnetic spectrum includes several regions: ultraviolet (UV), visible, infrared (IR), and far infrared (FIR). Each region corresponds to different energy levels of photons.

**Hint:** Recall the energy associated with different regions of the spectrum; visible light has energies that can promote electrons in d-orbitals.

### Step 4: Conclusion on Absorption
For colored complexes, the energy of visible light is typically suitable for promoting electrons from lower to higher d-orbitals. This means that colored complexes primarily absorb radiation in the visible region of the electromagnetic spectrum.

**Hint:** Consider why transition metals are often colored; it relates to their electronic transitions.

### Final Answer
Colored complexes absorb radiation in the **visible region**.