5 Facts On Beryllium Ionization Energy & Electronegativity

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Beryllium (Be) is the first element of the second group in the periodic table and is a soft metal. Let us study some facts about Be in detail.

Be generally shows 1st and 2nd ionizations, these ionization energies are 899.5 KJ/mol and 1757.1 KJ/mol, respectively, where the electrons are removed from the valence s-orbital for the first two ionizations. However, the energy for the third ionization is also reported.

Here, we will discuss the ionization energy and electronegativity of beryllium and will also make comparisons with that of other metals.

Beryllium first ionization energy

The first ionization energy of beryllium is 899.5 KJ/mol. For the first ionization, the electron is removed from the s-orbital, giving the resulting configuration [He]2s1.

Be → Be+ + e–

Beryllium second ionization energy

1757.1 KJ/mol is the second ionization energy of Be. The value is slightly higher as the electron is removed from an ionic species. After the removal of the 2nd electron, it attains a noble gas configuration as [He].

Be+ → Be2+ + e–

Beryllium ionization energy graph

The plot shows the 1st, 2nd, and 3rd ionization values for Be, where the 3rd ionization energy value is significantly higher due to the removal of the electron from a highly stable state.

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Ionization energy graph

Lithium and Beryllium ionization energy

Lithium is an element of group IA (alkali metals) so its ionization energy values will be different from that of Be as follows-

IonizationIonization energy of BeIonization energy of LiReasons
1st899.5 KJ/mol520.2 KJ/molIn both Li and Be, the electron is removed from the s-orbital. The value for Li is comparatively lower as they both belong to the second period and Li comes first in the period. As we move from left to right in a period, ionization energy increase due to the increase in effective nuclear charge.
2nd1757.1 KJ/mol7298.1 KJ/molThe second ionization energy for Li is significantly higher than that of Be as after the removal of 1st electron Li attains a noble gas state so it requires a high amount of energy to remove further electrons.
I.E. values

Beryllium electronegativity

  • The electronegativity of Be is 1.57 as per the Pauling scale.
  • Be is more electronegative than the other elements present in the IIA group (alkaline earth metals).
  • Be has a high affinity to attract the bonded pair of electrons so it makes a covalent bond rather than an ionic bond.

Conclusion

The ionization energy of Be is found to be higher than the same group metals like Mg, Ca, Sr, and Ba due to an increase in the number of shells. The alloys of Be are used to make springs and welding electrodes.