Question

The exception of beryllium (Be) having a higher first ionization energy than boron (B) can be explained in terms of:

A) Electron arrangements and attraction/repulsion
B) Electron affinity
C) Atomic mass and size
D) Atomic number and charge

Answer 1

The exception of beryllium (Be) having a higher first ionization energy than boron (B) can be explained by the electron arrangements and attraction/repulsion. An s electron is harder to remove from an atom than a p electron in the same shell.

Step-by-step explanation:

The exception of beryllium (Be) having a higher first ionization energy than boron (B) can be explained in terms of electron arrangements and attraction/repulsion. Within any one shell, the s electrons are lower in energy than the p electrons. This means that an s electron is harder to remove from an atom than a p electron in the same shell. The electron removed during the ionization of beryllium ([He]2s²) is an s electron, whereas the electron removed during the ionization of boron ([He]2s²2p¹) is a p electron; this results in a lower first ionization energy for boron, even though its nuclear charge is greater by one proton.