The first `(Delta_(i)H_(1))` and second `(Delta_(i)H_(2))` ionisation enthalpies `("in" kJ mol^(-1))` and the `(Delta_(eg)H^(ө))` electron gain enthalpy `("in" kJ mol^(-1))` of a few elements are given below:
`{:("Elements",(Delta_(i)H_(1)),(Delta_(i)H_(2)),Delta_(eg)H^(ө)),(I,520,7300,-60),(II,419,3051,-48),(III,1681,3374,-328),(IV,1008,1846,-295),(V,2372,5251,+48),(VI,738,1451,-40):}`
Which of the above elements is likely to be
a. the least reactive element.
b. the most reactive metal.
c. the most reactive non-metal.
d. the least reactive non-metal.
e. the metal which can form a stable binary halide of the formula `MX_2` (X=halogen).
f. the metal which can form a predominantly stable covalent halide of the formula MX(X=halogen).

Explanation

To solve the problem, we will analyze the given data for the elements I, II, III, IV, V, and VI based on their ionization enthalpies and electron gain enthalpy.

### Step-by-Step Solution:

1. **Identify the least reactive element**:
- The least reactive element will have the highest first ionization enthalpy and a positive or less negative electron gain enthalpy.
- From the data:
- Element I: \( \Delta_iH_1 = 520 \), \( \Delta_iH_2 = 7300 \), \( \Delta_{eg}H^{\circ} = -60 \)
...