The species which has its fifth ionization potential equal to 340 V is :

Options

A. `B^(+)`
B. `C^(+)`
C. `B`
D. `C`

Answer

To determine the species that has its fifth ionization potential equal to 340 V, we can follow these steps:

### Step 1: Understand Ionization Potential
Ionization potential (IP) is the energy required to remove an electron from an atom or ion. The fifth ionization potential (IP5) refers to the energy required to remove the fifth electron from an atom.

### Step 2: Identify the Number of Electrons
Since we are looking for the fifth ionization potential, we need to consider elements that have at least five electrons. This means the atomic number (Z) of the element must be at least 5.

### Step 3: Consider the Electron Configuration
The electron configuration of an element helps us understand how many electrons can be removed. For example:
- Boron (Z = 5) has the electron configuration: 1s² 2s² 2p¹
- Carbon (Z = 6) has the electron configuration: 1s² 2s² 2p²

### Step 4: Calculate the Ionization Potential
The formula for ionization potential is given by:
\[ IP = -\frac{13.6 Z^2}{n^2} \]
Where:
- \( Z \) is the atomic number
- \( n \) is the principal quantum number of the electron being removed

For the fifth ionization potential, we will consider the removal of the fifth electron, which will be from the first energy level (n = 1) after all valence electrons have been removed.

### Step 5: Set Up the Equation
Given that the fifth ionization potential is 340 V, we can set up the equation:
\[ 340 = -\frac{13.6 Z^2}{1^2} \]

### Step 6: Solve for Z
Rearranging the equation gives:
\[ Z^2 = \frac{340 \times 1^2}{13.6} \]
\[ Z^2 = \frac{340}{13.6} \]
\[ Z^2 = 25 \]
Taking the square root:
\[ Z = 5 \]

### Step 7: Identify the Element
The atomic number 5 corresponds to Boron (B). Therefore, the species that has its fifth ionization potential equal to 340 V is Boron.

### Final Answer
The species which has its fifth ionization potential equal to 340 V is Boron (B).

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