Question

which element in first transition series has highest 1. second ionisation enthalpy 2. third ionisation enthalpy

Answer 1

zinc has third in series

Answer 2

● Answer -
Highest 2nd ionization enthalpy => Cu
Highest 3rd ionization enthalpy => Zn

● Explaination -
# Highest 2nd ionization enthalpy -
- Electronic configuration of Cu is 3d10 4s1.
- First valence electron being free gets easily removed.
- For Cu, 2nd last is in complete stable octet.
- Therefore, large energy is required to remove it.
- Thus, Cu has highest 2nd ionization enthalpy.

# Highest 3rd ionization enthalpy -
- Electronic configuration of Zn is 3d10 4s2.
- 1st and 2nd valence electron being free get easily removed.
- For Cu, 3rd last is in complete stable octet.
- Therefore, large energy is required to remove it.
- Thus, Zn has highest 3rd ionization enthalpy.


Hope this helps you...