Write the electronic configuration of the element with atomic number of `9, 11, 21` and `36`. Preedict the folloiwng from these configurations:
(a) Which of them has the lowest ionisation potential ?
(b) Which of them has the hihest electron gain enthalpy ?
( c) Which of them are non-metals?
(d) Which of them has zero electron gain enthalpy ?

Explanation

To solve the question, we will first write the electronic configurations for the elements with atomic numbers 9, 11, 21, and 36. Then, we will analyze these configurations to answer the sub-questions regarding ionization potential, electron gain enthalpy, non-metals, and zero electron gain enthalpy.

### Step 1: Write the electronic configurations

1. **Atomic Number 9**:
- The electronic configuration is \(1s^2 2s^2 2p^5\).
- This corresponds to the element Fluorine (F).

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