The correct order of electron gain enthalpy is:
1. S > Se > Te > O
2. Te > Se > S > O
3. O > S > Se > Te
4. S > O > Se > Te
The first ionisation potential of Na is 5.1 eV. The value of electron gain enthalpy of Na+ will be -
1. – 10.2 eV
2. + 2.55 eV
3. – 2.55 eV
4. – 5.1 eV
In which of the following arrangements the order is not according to the property indicated against it?
| 1. | Li < Na < K < Rb : Increasing metallic radius |
| 2. | I < Br < F < Cl: Increasing electron gain enthalpy (with negative sign) |
| 3. | B < C < N < O: Increasing first ionisation enthalpy |
| 4. | Al3+ < Mg2+ < Na+ < F- : Increasing ionic size |
Arrange the following elements in decreasing order of their electron gain enthalpy (magnitude only):
| 1. | A>B>C>D | 2. | D>C>B>A |
| 3. | C>B>A>D | 4. | A>B>D>C |