Here's why:
* Boron's Electron Configuration: Boron has an atomic number of 5, meaning it has 5 electrons. Its electron configuration is 1s²2s²2p¹.
* Valence Electrons: Boron has three electrons in its outermost (valence) shell (2s²2p¹).
* Octet Rule: Atoms tend to gain, lose, or share electrons to achieve a stable configuration of eight electrons in their valence shell (the octet rule).
* Boron's Stability: Boron can achieve stability by sharing its three valence electrons with three hydrogen atoms, forming three covalent bonds. This creates a molecule of borane (BH₃), where boron has a full outer shell of six electrons.
Therefore, a boron atom needs three hydrogen atoms to form covalent bonds and attain a stable electron configuration.
