Mendeleev
Periodic table · chemistry · physics
Element story

Magnesium

Atomic number 12 means that every Magnesium nucleus contains 12 protons. That proton count is the element's identity: change it and you no longer have Magnesium.

Start with the nucleus

Atomic number 12 means that every Magnesium nucleus contains 12 protons. That proton count is the element's identity: change it and you no longer have Magnesium.

Magnesium (Mg) is chemical element 12. It belongs to the alkaline-earth metals, 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 alloys, fireworks and biology.

See the atom

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

What this number means

Atomic number 12 means that every Magnesium nucleus contains 12 protons. That proton count is the element's identity: change it and you no longer have Magnesium.

Keep exploring

→ Magnesium · Atomic structure · Periodic trends

12MgMagnesium
Magnesium · Mg · Z = 12

Magnesium (Mg) is chemical element 12. It belongs to the alkaline-earth metals, 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

Magnesium (Mg) is chemical element 12. It belongs to the alkaline-earth metals, 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 alloys, fireworks and biology.

What its position in the table tells us

Magnesium sits in period 3, group 2 and the S block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.