Among the elements of second period i.e. from Li to Ne, pick out the elements:
(a) with the highest first ionisation enthalpy
(b) with the highest electronegativity
(c) with the largest atomic radius
(d) which is the most reactive non-metal
(e) which is the most reactive metal ?
The elements of the second period are:
Li, Be, B, C, N, O, F, Ne
(a) The element with highest first ionisation enthalpy: Neon (Ne).
(b) The element with highest electronegativity: Fluorine (F).
(c) The element with largest atomic radius: Lithium (Li).
(d) The most reactive non-metal: Fluorine (F).
(e) The most reactive metal: Lithium (Li).
The first (IE1) and second (IE2) ionisation enthalpies (kJ mol-1) of a few elements by Roman numerals are as shown:
IE1 | IE2 | |
i | 2372 | IE2 |
ii | 520 | 7300 |
iii | 900 | 1760 |
iv | 1680 | 380 |
which of the above elements is likely to be:
(i) a reactive metal
(ii) a reactive non-metal
(iii) a noble gas
(iv) a metal that forms a stable binary halide of the formula AX3 (X = halogen).
The first ionization enthalpy values (in kJ mol-1) of group 13 elements are:
B Al Ga In Tl
801 577 579 558 589
How would you explain this deviation from the general trend?
Arrange the following in order of increasing ionisation enthalpies and assign reason:
(i) K+, Ar, Cl-
(ii) Fe, Fe2+, Fe3+
Which of the following pairs of elements would you expect to have lower first ionisation enthalpy? Explain your answer:
(a) Cl or F
(b) Cl or S
(c) K or Ar
(d) Kr or Xe.
How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?