While going down in the group of non-metals (14, 15, 16 and 17) the electronegative character of non-metals decreases. Typical example is of group 15 elements. The elements nitrogen (2nd period) and phosphorus (3rd period) are non-metals and their oxides are acidic in nature. The elements arsenic (4th period) and antimony (5th period) are metalloids and their oxides are amphoteric in nature. However, bismuth (6th period) is a metal. Thus, we can see that the electronegative character (non-metallic character) of elements gradually decreases and ultimately the last element becomes metal. In case of group 17 of halogens, the first member of the group i.e., fluorine is most non-metallic in character and last member of group, i.e., astatine is least non-metallic in character. In other words, the electronegative nature of the elements decreases as we move down the group.
Which of the following is the most metallic element?

Options

A. P
B. N
C. Bi
D. As

Answer

To determine which of the following is the most metallic element among nitrogen, phosphorus, arsenic, and bismuth, we can follow these steps:

### Step 1: Understand Metallic Character
Metallic character refers to the tendency of an element to lose electrons easily. The more easily an element can lose electrons, the more metallic it is.

### Step 2: Analyze the Group Trend
In the periodic table, as we move down a group, the atomic size increases because additional electron shells are added. This increase in size affects the effective nuclear charge (Z-effective) experienced by the outermost electrons.

### Step 3: Consider Effective Nuclear Charge
When the atomic size increases, the effective nuclear charge (Z-effective) experienced by the valence electrons decreases. This means that the outermost electrons are held less tightly by the nucleus, making them easier to lose.

### Step 4: List the Elements in Question
The elements in question are:
- Nitrogen (N) - 2nd period
- Phosphorus (P) - 3rd period
- Arsenic (As) - 4th period
- Bismuth (Bi) - 6th period

### Step 5: Determine the Most Metallic Element
As we move down the group from nitrogen to bismuth:
- Nitrogen is the least metallic because it is at the top of the group.
- Phosphorus is more metallic than nitrogen.
- Arsenic is more metallic than phosphorus.
- Bismuth, being the lowest in the group, is the most metallic of all.

### Conclusion
Thus, the most metallic element among nitrogen, phosphorus, arsenic, and bismuth is **Bismuth (Bi)**.

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