Mendeleev
Periodic table · chemistry · physics
Element story

Technetium

Atomic number 43 means that every Technetium nucleus contains 43 protons. That proton count is the element's identity: change it and you no longer have Technetium.

Start with the nucleus

Atomic number 43 means that every Technetium nucleus contains 43 protons. That proton count is the element's identity: change it and you no longer have Technetium.

Technetium (Tc) is chemical element 43. It belongs to the transition 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 medical imaging equipment, scientific research and nuclear medicine.

See the atom

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

What this number means

Atomic number 43 means that every Technetium nucleus contains 43 protons. That proton count is the element's identity: change it and you no longer have Technetium.

Keep exploring

→ Technetium · Atomic structure · Periodic trends

43TcTechnetium
Technetium · Tc · Z = 43

Technetium (Tc) is chemical element 43. It belongs to the transition 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

Technetium (Tc) is chemical element 43. It belongs to the transition 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 medical imaging equipment, scientific research and nuclear medicine.

What its position in the table tells us

Technetium sits in period 5, group 7 and the D block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.