![Boron element card: symbol B, atomic number 5, atomic mass 10.81, electron configuration [He] 2s² 2p¹, oxidation states +3, Metalloid, group 13, period 2, solid at room temperature.](https://stage.chemistry-dictionary.com/wp-content/uploads/2026/09/boron-chemical-element.webp)
Boron sits in group 13 of the periodic table as a unique metalloid. A metalloid is an element that shares physical properties with both metals and nonmetals. Boron exists in several distinct forms, which scientists call allotropes.
Amorphous boron appears as a fine brown powder, while crystalline boron is a hard, black, brittle solid. Chemically, boron has only three outer valence electrons available for making chemical bonds. It tends to form covalent bonds to share its electrons with other atoms.
This sharing behavior creates complex, three-dimensional network structures instead of simple ionic compounds. Many students incorrectly assume that boron behaves like a typical metal since it is near aluminum. However, its small atomic size makes it behave more like carbon or silicon.
We find boron in dried desert lakes as minerals like borax and kernite. People use borax compounds in household cleaning products, laundry boosters, and pest control formulas. It is also an essential nutrient that helps plants build strong, rigid cell walls.
In addition, the special boron-10 isotope can absorb free neutrons without splitting apart. This rare property makes it very useful for control rods that regulate nuclear reactors.