Cation and anion combines in a crystal to form following type of compound

Options

A. lonic
B. metallic
C. covalent
D. dipole -dipole

Answer

To determine the type of compound formed when a cation and anion combine in a crystal, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Cations and Anions**:
- A **cation** is a positively charged ion formed when an atom loses one or more electrons.
- An **anion** is a negatively charged ion formed when an atom gains one or more electrons.

2. **Formation of Ionic Compounds**:
- Ionic compounds are formed when cations and anions interact. This typically occurs when:
- A metal (which tends to lose electrons and form cations) reacts with a non-metal (which tends to gain electrons and form anions).
- The metal donates electrons to the non-metal, resulting in the formation of cations and anions.

3. **Crystal Lattice Structure**:
- In a crystal lattice, cations and anions are arranged in a three-dimensional structure. The electrostatic attraction between the oppositely charged ions holds the lattice together.
- This arrangement maximizes the attraction between cations and anions while minimizing repulsion between like charges.

4. **Identifying the Type of Compound**:
- Given that cations and anions combine to form a compound, the type of compound formed is an **ionic compound**.
- Therefore, the correct answer to the question is **ionic**.

5. **Exclusion of Other Options**:
- **Metallic Compounds**: Formed by the bonding of metal atoms with free electrons, not involving cations and anions.
- **Covalent Compounds**: Formed by the sharing of electrons between atoms, rather than the transfer of electrons.
- **Dipole-Dipole Interactions**: Occur between polar molecules due to partial charges, not involving cations and anions.

### Final Answer:
The type of compound formed when a cation and anion combine in a crystal is **ionic**.

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