`(X), (Y), (Z)` are elements in third short period. Oxide of `(X)` is ionic, `(Y)` is amphoteric and `(Z)` is a giant molecule. `(X), (Y)` and `(Z)` will have atomic number in the order :

Options

A. `(X) lt (Y) lt (Z)`
B. `(Z) lt (Y) lt (X)`
C. `(X) lt (Z) lt (Y)`
D. `(Y) lt (X) lt (Z)`

Explanation

To solve the question, we need to identify the elements (X), (Y), and (Z) based on the properties of their oxides and their positions in the third period of the periodic table.

### Step-by-Step Solution:

1. **Identify the Elements in the Third Period**:
The elements in the third period (from left to right) are:
- Sodium (Na, atomic number 11)
- Magnesium (Mg, atomic number 12)
- Aluminum (Al, atomic number 13)
- Silicon (Si, atomic number 14)
- Phosphorus (P, atomic number 15)
- Sulfur (S, atomic number 16)
- Chlorine (Cl, atomic number 17)
- Argon (Ar, atomic number 18)

2. **Determine the Properties of the Oxides**:
- **Element (X)**: The oxide of (X) is ionic. The ionic oxides in the third period are:
- Sodium oxide (Na2O)
- Magnesium oxide (MgO)
- **Element (Y)**: The oxide of (Y) is amphoteric. The amphoteric oxide in the third period is:
- Aluminum oxide (Al2O3)
- **Element (Z)**: The oxide of (Z) is a giant molecule. The giant molecular oxide in the third period is:
- Silicon dioxide (SiO2)

3. **Assign Elements to (X), (Y), and (Z)**:
- Since both sodium and magnesium have ionic oxides, we can consider (X) as sodium (Na) because sodium oxide (Na2O) is more ionic than magnesium oxide (MgO).
- (Y) is aluminum (Al) since its oxide (Al2O3) is amphoteric.
- (Z) is silicon (Si) because its oxide (SiO2) is a giant molecular structure.

4. **List the Atomic Numbers**:
- For (X) = Sodium (Na) → Atomic number = 11
- For (Y) = Aluminum (Al) → Atomic number = 13
- For (Z) = Silicon (Si) → Atomic number = 14

5. **Determine the Order of Atomic Numbers**:
The order of atomic numbers is:
- (X) < (Y) < (Z)
- 11 (Na) < 13 (Al) < 14 (Si)

### Final Answer:
The atomic numbers of (X), (Y), and (Z) are in the order: **X < Y < Z**.