In Which Of The Following Arrangement The Order Is Not According To The Property Indicated Against It?

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In which of the following arrangement the order is not according to the property indicated against it?


Correct option is

B < C < N < O: Increasing first ionisation enthalpy


(a) Metallic radii increase in a group from top to bottom.

     Thus,                Li < Na < K < Rb is true 

(b) Electron gain enthalpy of Cl > F and decreases along a group.

      Thus,               I < Br < F < Cl is true.  

(c) Ionisation enthalpy increases along a period from left to right but due to presence of half-filled orbital in N, ionisation enthalpy of N > O.

Thus, B < C < N < O is incorrect.



Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species?


Which is likely to show inert pair effect?


The correct order of the size of iodine species is


In which one of the following pairs the radius of the second species is greater than that of the first?


The increasing order of the first ionisation enthalpies of elements B, P, S and F (lowest first) is


The element having highest electron affinity is


Diagonal relationship is for


The correct order according to size is



The successive ionisation energy values for an element ‘X’ are given below: 

1st ionisation energy = 410 kJ mol–1

2nd ionisation energy = 820 kJ mol–1

3rd ionisation energy = 1100 kJ mol–1

4th ionisation energy = 1500 kJ mol–1

5th ionisation energy = 3200 kJ mol–1

Find out the number of valence electrons for the atom ‘X’. 


Which is the correct order of electronegativity?