Ionization Energy Calculator
Calculate first, second, and third ionization energies. Determine threshold wavelengths for photoionization.
Element Selection
Enter to check if photoionization is possible
Elements by IE1:
First Ionization Energy (IE1)
496 kJ/mol
5.14 eV | Threshold: 241.4 nm
1IE1
496 kJ/mol
2IE2
4562 kJ/mol
3IE3
6910 kJ/mol
VValence e-
1
Large IE jump after removing 1 electron(s)
This indicates 1 valence electron(s)
Ionization Energy Trends
Across a Period
Generally increases due to increasing nuclear charge and decreasing atomic radius.
Down a Group
Generally decreases due to increasing atomic radius and shielding effect.