Which of the following is arranged in order of increasing metallic character?

Options

A. `PltSiltNaltBeltMg`
B. `BeltMgltPltNaltSi`
C. `SiltBegtMgltNaltP`
D. `PltSiltBeltMgltNa`

Explanation

To determine the order of increasing metallic character among the given elements, we need to understand how metallic character varies in the periodic table.

### Step-by-Step Solution:

1. **Understanding Metallic Character**:
- Metallic character refers to the tendency of an element to lose electrons and form positive ions (cations). Metals are typically malleable, ductile, good conductors of heat and electricity, and have a lustrous appearance.

2. **Trends in the Periodic Table**:
- **Down a Group**: As you move down a group in the periodic table, metallic character increases. This is because the atomic size increases, making it easier for the atom to lose electrons.
- **Across a Period**: As you move from left to right across a period, metallic character decreases. This is due to the increase in effective nuclear charge, which makes it harder for the atom to lose electrons.

3. **Identifying the Elements**:
- Let's consider the elements mentioned: Sodium (Na), Magnesium (Mg), Beryllium (Be), Silicon (Si), and Phosphorus (P).
- Sodium (Na) is in Group 1 (alkali metals).
- Magnesium (Mg) is in Group 2 (alkaline earth metals).
- Beryllium (Be) is also in Group 2 but is higher up in the periodic table.
- Silicon (Si) is in Group 14 (metalloids).
- Phosphorus (P) is in Group 15 (non-metals).

4. **Arranging the Elements**:
- Based on the trends:
- Sodium (Na) has the highest metallic character because it is an alkali metal.
- Magnesium (Mg) follows, as it is also a metal but has a higher effective nuclear charge than sodium.
- Beryllium (Be) has lower metallic character than magnesium because it is higher up in the group.
- Silicon (Si) has even lower metallic character as it is a metalloid.
- Phosphorus (P) has the lowest metallic character as it is a non-metal.

5. **Final Order**:
- The order of increasing metallic character is: Phosphorus (P) < Silicon (Si) < Beryllium (Be) < Magnesium (Mg) < Sodium (Na).

### Conclusion:
The correct arrangement of the elements in order of increasing metallic character is:
**Phosphorus < Silicon < Beryllium < Magnesium < Sodium**.