The values of `IE_1 , IE_2 , IE_3, IE_4` and `IE_5` of an element are 8.1, 14.3, 34.5, 46.8 and 162.2 eV respectively. The element is likely to be:

Options

A. Na
B. Si
C. F
D. Ca

Answer

To determine which element corresponds to the given ionization energies (IE), we can analyze the provided values of ionization enthalpy step by step.

### Step 1: Understanding Ionization Energies
Ionization energy (IE) is the energy required to remove an electron from an atom in its gaseous state. The first ionization energy (IE1) is the energy needed to remove the first electron, the second ionization energy (IE2) is for the second electron, and so on.

### Step 2: Analyzing the Given Ionization Energies
The given values are:
- IE1 = 8.1 eV
- IE2 = 14.3 eV
- IE3 = 34.5 eV
- IE4 = 46.8 eV
- IE5 = 162.2 eV

### Step 3: Observing Trends in Ionization Energies
1. **IE1 to IE2**: The increase from 8.1 eV to 14.3 eV is significant but not drastic.
2. **IE2 to IE3**: The increase from 14.3 eV to 34.5 eV is larger, indicating that removing the third electron is more difficult than removing the second.
3. **IE3 to IE4**: The increase from 34.5 eV to 46.8 eV is again significant but not as large as the previous jump.
4. **IE4 to IE5**: The jump from 46.8 eV to 162.2 eV is very large, indicating that after removing four electrons, the atom achieves a stable electron configuration (likely a noble gas configuration).

### Step 4: Inferring the Element
The large jump in ionization energy between IE4 and IE5 suggests that after removing four electrons, the element reaches a stable configuration. This is characteristic of elements that have a noble gas configuration after losing a certain number of electrons.

### Step 5: Identifying Possible Elements
- **Silicon (Si)** has the electronic configuration of \(1s^2 2s^2 2p^6 3s^2 3p^2\).
- Removing four electrons from silicon (two from 3s and two from 3p) results in the configuration of \(1s^2 2s^2 2p^6\) (noble gas configuration).
- The large increase in IE5 indicates that removing the fifth electron from the noble gas configuration requires significantly more energy.

### Conclusion
Based on the analysis of the ionization energies and the electronic configuration, the element is likely to be **Silicon (Si)**.