Boron is a chemical element with the symbol B and atomic number 5. It's a metalloid, which means it has properties of both metals and non-metals.
Metalloid: A type of chemical element which has properties in between or that are a mixture of those of metals and nonmetals.
The number of protons found in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
Chemical Element: A species of atoms having the same number of protons in their atomic nuclei.