# What is the electronic configuration of the boron atom?

Boron, $Z = 5$, has 3 electrons in its valence shell, i.e. its atomic configuration is $1 {s}^{2} 2 {s}^{2} 2 {p}^{1}$. The $2 s$ and $2 p$ valence electrons are conceived to hybridize to give THREE $s {p}^{2}$ hybrid orbitals, and to a first approximation boron forms 3 covalent bonds, i.e. to give $B {H}_{3}$, or $B {X}_{3}$, or $B {R}_{3}$.
Of course this is to a first approximation. Boron is known to undergo electron-deficient bonding, with $\text{3-centre, 2-electron bonds}$ between boron and hydrogen featured.