What is the valency of Boron?

3

The correct answer is option (2) 3.

Valency refers to the combining capacity of an atom, indicating the number of bonds it can form with other atoms.

Boron has an atomic number of 5, which means it has 5 protons and 5 electrons.

Its electronic configuration is 1s²2s²2p¹, which signifies 2 electrons in the first shell (K shell), 2 electrons in the second shell (L shell), and 1 electron in the outermost shell (valence shell).

Since achieving a stable electron configuration (octet rule) is favorable, Boron tends to lose its 3 valence electrons to form covalent bonds with other atoms.

Therefore, the valency of Boron is 3.