Consider the following statements and arrange in the order of true/false as given in the codes.
`S_1:Na_2O_2ltMgOltZnOltP_4O_(10)`:Acidic property.
`S_2:NaltSigtMgltAl`:First ionisation energy.
`S_3:FgtClgtBr`:Electron affinity.

Options

A. TTT
B. TTF
C. TFF
D. TFT

Explanation

To solve the problem, we need to analyze each statement provided and determine whether they are true or false based on our knowledge of chemistry.

### Step-by-Step Solution:

1. **Analyzing Statement S1: `Na2O2 < MgO < ZnO < P4O10`: Acidic Property**
- The acidic property of oxides generally increases as we move from metals to non-metals in the periodic table.
- Sodium oxide (Na2O) is a basic oxide, magnesium oxide (MgO) is amphoteric, zinc oxide (ZnO) is also amphoteric but leans towards acidic behavior, and phosphorus pentoxide (P4O10) is an acidic oxide.
- Therefore, the order of acidic property from least to most acidic is indeed:
- Na2O < MgO < ZnO < P4O10.
- **Conclusion**: Statement S1 is **True**.

2. **Analyzing Statement S2: `Na < Si < Mg < Al`: First Ionisation Energy**
- The first ionization energy generally increases across a period (left to right) and decreases down a group (top to bottom).
- In this case, sodium (Na) has the lowest ionization energy, followed by magnesium (Mg), then aluminum (Al), and silicon (Si) has a higher ionization energy than both aluminum and magnesium.
- The correct order should be:
- Na < Mg < Al < Si.
- **Conclusion**: Statement S2 is **False**.

3. **Analyzing Statement S3: `F > Cl > Br`: Electron Affinity**
- Electron affinity generally increases across a period and decreases down a group. However, there is an exception between fluorine (F) and chlorine (Cl).
- Fluorine has a smaller atomic size, which makes it less able to accommodate an additional electron compared to chlorine, resulting in chlorine having a higher electron affinity than fluorine.
- The correct order of electron affinity is:
- Cl > F > Br.
- **Conclusion**: Statement S3 is **False**.

### Final Order of Statements:
- S1: True
- S2: False
- S3: False

### Answer:
The order of true/false statements is:
- S1: True
- S2: False
- S3: False

Thus, the correct answer is **C**.