List of top Chemistry Questions on Periodicity of Elements

First ionisation enthalpy values of the first four group 15 elements are given below. Choose the correct value for the element that is a main component of the apatite family:
The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is:
In group 17, which property does not follow the regular trend?
The increasing order of molarity of 25 gm each of:
(A) \( \text{NaOH} \)
(B) \( \text{LiOH} \) 
(C) \( \text{KOH} \) 
(D) \( \text{Al(OH)}_3 \) 
(E) \( \text{B(OH)}_3 \)
in the same volume of water is:
Choose the correct answer from the options given below:
Which of the following species has the highest electron affinity?
The correct order of decreasing ionic radii among the following isoelectronic species
  1. \(K^+, \, Ca^{2+}, \, Cl^-, \, S^{2-}\)
  2. \(K^+, \, Cl^-, \, Ca^{2+}, \, S^{2-}\)
  3. \(S^{2-}, \, Ca^{2+}, \, Cl^-, \, K^+\)
  4. \(S^{2-}, \, Cl^-, \, K^+, \, Ca^{2+}\)
Choose the correct answer from the options given below:
Electronegativity of the following elements increases in the order
(A). C
(B). N
(C). Si
(D). P
Choose the correct answer from the options given below:
For elements B, C, N, Li, Be, O and F, the correct order of first ionization enthalpy is: