What will be the correct order of size for the given elements ?

Options

A. Option 1. `Na lt Cl lt F`
B. Option 2. `Na lt F lt Cl`
C. Option 3. `F lt Cl lt Na`
D. Option 4. `Cl lt F lt Na`

Answer

To determine the correct order of size for the given elements (sodium, fluorine, and chlorine), we can follow these steps:

### Step 1: Identify the Group and Period of Each Element
- Sodium (Na) is in Group 1 (alkali metals) and Period 3.
- Fluorine (F) is in Group 17 (halogens) and Period 2.
- Chlorine (Cl) is in Group 17 (halogens) and Period 3.

### Step 2: Understand the Trend in Atomic Size
- Atomic size decreases across a period (from left to right) due to increasing nuclear charge, which pulls the electrons closer to the nucleus.
- Atomic size increases down a group due to the addition of new electron shells.

### Step 3: Compare the Sizes of the Elements
- Sodium (Group 1, Period 3) will be larger than both fluorine and chlorine because it is to the left of both in the periodic table.
- Between fluorine and chlorine, chlorine (Group 17, Period 3) will be larger than fluorine (Group 17, Period 2) because chlorine has an additional electron shell compared to fluorine.

### Step 4: Establish the Correct Order of Size
Based on the above comparisons, we can arrange the elements in order of size:
1. Sodium (Na) - largest
2. Chlorine (Cl) - second largest
3. Fluorine (F) - smallest

Thus, the correct order of size from largest to smallest is:
**Na > Cl > F**

### Final Answer
The correct order of size for the given elements is:
**Na > Cl > F**

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