Which of the following elements has more negative electron gain enthalpy?
(i) [Ne] 3s²sp³
(ii) [Ne] 3s²3p⁴
(iii) [Ne] 3s² 3p⁵

Which of the following pairs of elements would have a more negative electron gain enthalpy?
(i) O or F    (ii) F or Cl

What is the significance of the terms - "isolated gaseous atom' and 'ground state' while defining the ionization enthalpy and electron gain enthalpy?

154.

Explain, which of the following pairs of elements would have a more negative electron gain enthalpy:
(i) N or O     (ii) O or S

Using the periodic table predicts the formulae of compounds which might be formed by the following pairs of elements:

(a) Silicon and bromine.

(b) Aluminium and sulphur.

The electron gain enthalpy of chlorine is 3.7 eV per atom. How much enthalpy in kJ is released when 1g of chlorine is converted completely of Cl^- ion in the gaseous state?

Differentiate between ionisation enthalpy and electron gain enthalpy ?

Write the electronic configuration of the elements with Z = 9, 11 and 36. Predict the following from the configuration:

(i) Which of them has the large negative value of electron gain enthalpy?

(ii) Which of them has the lowest ionisation enthalpy?

(iii) Which has positive electron gain enthalpy?

Use the periodic table to answer the following questions:

(a) Identify an element with five electrons in the outer subshell.

(b) Identify an element that would tend to lose two electrons.

(c) Identify an element that would tend to gain two electrons.

(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature. 

The increasing order of reactivity among group 1 elements is Li < Na < K < Rb is F > CI > Br > I. Explain.