The ionisation energy will be higher when the electron is removed from:

Options

A. s-orbital
B. p-orbital
C. d-orbital
D. f-orbital

Answer

To determine from which orbital the ionization energy will be higher when an electron is removed, we need to consider the following steps:

### Step 1: Understand Ionization Energy
Ionization energy is defined as the amount of energy required to remove an electron from an atom in its gaseous state. It is influenced by several factors, including the type of orbital from which the electron is being removed.

### Step 2: Identify the Orbitals
The question presents four types of orbitals:
- s orbital
- p orbital
- d orbital
- f orbital

### Step 3: Analyze the Position of Electrons in Orbitals
Electrons in different orbitals experience different levels of nuclear charge:
- **s orbitals** are closest to the nucleus and thus experience the highest nuclear charge.
- **p orbitals** are next, followed by **d orbitals**, and then **f orbitals**, which are the farthest from the nucleus.

### Step 4: Compare Ionization Energies
- Electrons in **s orbitals** are held more tightly by the nucleus due to their proximity, requiring more energy to remove them.
- Electrons in **p orbitals** require less energy than s orbitals but more than d and f orbitals.
- **d and f orbitals** have electrons that are further away from the nucleus and thus experience less nuclear charge, making them easier to remove.

### Step 5: Conclusion
Since the ionization energy is highest for electrons in the **s orbital**, followed by **p**, then **d**, and finally **f**, we conclude that the ionization energy will be higher when the electron is removed from the **s orbital**.

### Final Answer:
The ionization energy will be higher when the electron is removed from the **s orbital**.

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