Transition metal compounds are usually coloured This is due to the electronic transition .

Options

A. From d-orbital to s-orbital
B. From p-orbital to s-orbital
C. From d-orbital to s-orbital
D. Within the d-orbital

Answer

To solve the question regarding why transition metal compounds are usually colored due to electronic transitions, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Transition Metals**:
Transition metals are elements found in the d-block of the periodic table. They are characterized by the presence of d electrons.

**Hint**: Recall the position of transition metals in the periodic table and their general properties.

2. **Partially Filled d-Orbitals**:
The color in transition metal compounds arises primarily because they have partially filled d-orbitals. This means that there are unpaired electrons in the d-orbitals that can participate in electronic transitions.

**Hint**: Think about the electron configuration of transition metals and how many d electrons they typically have.

3. **Electronic Transitions**:
When light hits a transition metal compound, electrons in the d-orbitals can absorb energy and get excited to higher energy d-orbitals. This process is known as electronic transition.

**Hint**: Consider what happens to electrons when they absorb energy from light.

4. **Absorption of Light**:
The energy absorbed corresponds to specific wavelengths of light. The color observed in the compound is the complementary color of the light absorbed. For example, if a compound absorbs light in the red region, it will appear green.

**Hint**: Remember the color wheel and how complementary colors work.

5. **Emission of Light**:
After the electronic transition, when the electrons return to their lower energy state, they may emit light. However, the color we see is primarily due to the light that is not absorbed.

**Hint**: Think about how the emission of light relates to the color we perceive.

6. **Conclusion**:
Therefore, the color of transition metal compounds is due to electronic transitions occurring within the d-orbitals, specifically from one d-orbital to another.

**Hint**: Summarize the entire process: absorption of light leads to electronic transitions, resulting in the color observed.

### Final Answer:
The electronic transitions responsible for the color in transition metal compounds occur within the d-orbitals.