21. According to your web page, the first ionization energy of astatine is 20KJ / mol. 22. Both of these factors further increase the ionization energy . 23. In 2015, the first ionization energy of lawrencium was measured, using the isotope 256 Lr. 24. Excited-state ionization energies can be measured by photoelectron spectroscopy. 25. Elements in the same period show trends in atomic radius, ionization energy , electron affinity, and electronegativity. 26. Elements in the same group tend to show patterns in atomic radius, ionization energy , and electronegativity. 27. Caesium has the lowest measured ionization energy of all the elements and helium has the greatest. 28. But would the first ionization energy of Cl + be equal to 349 kJ / mol? 29. Likewise, would the electron affinity of Cl-be related to that first ionization energy of Cl neutral? 30. The structural chemistry of boron is dominated by its small atomic size, and relatively high ionization energy .
