The loss of water of crystallization to the atmosphere by a compound is termed

Options

A. deliquescence
B. dehydration
C. efflorescence
D. hydrolysis

Explanation

### Step-by-Step Solution:

1. **Understanding the Concept**: The question asks for the term that describes the loss of water of crystallization from a compound to the atmosphere. Water of crystallization refers to the water molecules that are part of the crystalline structure of certain compounds.

2. **Identifying Related Processes**:
- **Deliquescence**: This is when a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water, forming a solution. This is not what we are looking for.
- **Dehydration**: This refers to the removal of water from a reactant, but it typically results in the formation of an unsaturated compound. This does not apply here since we are not forming an unsaturated compound.
- **Efflorescence**: This is the process where a compound loses its water of crystallization to the atmosphere, which is exactly what the question is asking about.
- **Hydrolysis**: This refers to a reaction with water, which is also not relevant to the loss of water of crystallization.

3. **Conclusion**: Based on the definitions and processes discussed, the correct term for the loss of water of crystallization to the atmosphere by a compound is **efflorescence**.

### Final Answer:
The loss of water of crystallization to the atmosphere by a compound is termed **efflorescence**.

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