43
Tc
Transition metal

Technetium

Atomic number 43 · Period 5 · Block D

Tc · Technetium
Mendeleev.com

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.

medical imaging equipmentscientific researchnuclear medicine
Standard atomic weightNo standard atomic weight

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.

Worth remembering
Technetium is radioactive, so its chemistry cannot be separated from nuclear physics and radiation safety

Scientific sources

Element identity
Atomic number43
Group7
Period5
BlockD
CategoryTransition metal
PhaseSolid