Question

Maximum difference between first ionisation enthalpy is observed for the pair :

1) Li and Na
2) Na and K
3)K and Rb
4)Rb and Cs

Helping fast would be really appreciated​

Answer 1

Answer is option 1

i.e Li and Na

hope this helps u

Answer 2

Maximum difference between first ionisation enthalpy is observed for the pair:

1) $Li$ and $Na$

Explanation:

• Ionization enthalpy is the energy required to remove an electron from a neutral gaseous atom inorder to convert it into an unipositive ion.
• Ionization energy decreases down a group.
• This is because the number of shells increases down a group as a result atomic radius also increases.
• So the elements present at the top of a group will have maximum ionization energies than the elements which are present at the bottom part of a group.
• This is because elements at the top of a group have smaller size than the elements present at the bottom.
• Hence lithium and sodium will have higher ionization enthalpies compared to the other elements present in the group.
• So the maximum difference between first ionisation enthalpy is observed for the pair,Lithium and Sodium.