Short Answer TypeWhich of the following elements has more negative electron gain enthalpy?
(i) [Ne] 3s2sp3
(ii) [Ne] 3s23p4
(iii) [Ne] 3s2 3p5
Long Answer TypeWhich 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?
Short Answer TypeExplain, 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?
Long Answer TypeShort Answer TypeWrite 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?
Long Answer TypeUse 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.
(a) The general electronic configuration of the elements having five electrons in the outermost subshell is ns2np3. This electronic configuration is characteristic of elements of group 15. Hence element belongs to nitrogen family (group 15).
(b) The elements which have a tendency to lose two electrons must have two electrons in the valence shell. Therefore their general electronic configuration should be ns2. This electronic configuration is characteristic of elements of group 2. Hence element belongs to alkaline earth family (Group 2).
(c) The elements which have a tendency to gain two electrons must have six electrons in the valence shell. Therefore their general electronic configuration is ns2np4. This electronic configuration is characteristic of group 16 elements. Hence element belongs to oxygen family (Group 16).
(d) A metal which is liquid at room temperature is mercury and belongs to group 12. A non-metal which is gas at room temperature is nitrogen (Group 15), oxygen (Group 16), flourine and chlorine (Group 17) and inert gases (Group 18). A non-metal which is liquid at room temperature is bromine (Group 17).
The increasing order of reactivity among group 1 elements is Li < Na < K < Rb is F > CI > Br > I. Explain.
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