Video Transcript
What is the highest occupied atomic
orbital in an atom of boron?
Atomic orbitals are mathematical
expressions that describe the location of an electron in an atom. In this question, we need to
determine the highest occupied atomic orbital in an atom of boron. In an atom, electrons fill atomic
orbitals in order of increasing energy, which is summarized by this diagram. The different subshells hold a
different maximum number of electrons. The s subshell can hold a maximum
of two electrons; the p subshell, a maximum of six; d, 10; and f, 14.
Atoms of boron have five
electrons. The electrons will first fill the
lowest-energy atomic orbital which is the 1s orbital. The 1s orbital can hold two
electrons, which we indicate with a superscript. The next highest energy orbital is
the 2s orbital, which can also hold two electrons. Boron’s fifth and final electron
will go in the next highest energy subshell, which is the 2p subshell. From the electron configuration of
boron that we just came up with, we can see the highest occupied atomic orbital is
the 2p orbital.
