Boron has an electron configuration of 1s²2s²2p¹. Here's how to determine its electron spin:

* Orbitals: Boron has one electron in its 2p orbital.

* Spin: Each orbital can hold a maximum of two electrons, and these electrons have opposite spins. We represent spin with arrows: ↑ (spin up) and ↓ (spin down).

* Boron's spin: Since boron has only one electron in its 2p orbital, its spin is simply ↑ (spin up).

Therefore, the electron spin for boron is spin up.