109
Mt
Unknown

Meitnerium

Atomic number 109 · Period 7 · Block D

Mt · Meitnerium
Mendeleev.com

Understanding the element

Meitnerium (Mt) is chemical element 109. It belongs to the elements whose chemistry is still being explored, and its reference state at room temperature is not firmly established. 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 scientific research.

scientific research
Standard atomic weightNo standard atomic weight

What its position in the table tells us

Meitnerium sits in period 7, group 9 and the D block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.

Worth remembering
Meitnerium is synthetic, very short-lived and studied atom by atom in nuclear-physics laboratories

Scientific sources

Element identity
Atomic number109
Group9
Period7
BlockD
CategoryUnknown
PhaseUnknown