Mendeleev
Periodic table · chemistry · physics
Element story

Boron

Atomic number 5 means that every Boron nucleus contains 5 protons. That proton count is the element's identity: change it and you no longer have Boron.

Start with the nucleus

Atomic number 5 means that every Boron nucleus contains 5 protons. That proton count is the element's identity: change it and you no longer have Boron.

Boron (B) is chemical element 5. It belongs to the metalloids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

In practice, it turns up most often in borosilicate glass, glass fibre and plant nutrition.

See the atom

Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.

What this number means

Atomic number 5 means that every Boron nucleus contains 5 protons. That proton count is the element's identity: change it and you no longer have Boron.

Keep exploring

→ Boron · Atomic structure · Periodic trends

5BBoron
Boron · B · Z = 5

Boron (B) is chemical element 5. It belongs to the metalloids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

Understanding the element

Boron (B) is chemical element 5. It belongs to the metalloids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

Where do we encounter it?

In practice, it turns up most often in borosilicate glass, glass fibre and plant nutrition.

What its position in the table tells us

Boron sits in period 2, group 13 and the P block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.