Meitnerium (Mt)

Element 109 · transition metal · group 9, period 7

• 109 protons
• 2/9 valence e−
• d-block

Properties

Electron configuration of meitnerium

Orbitals fill from the lowest energy upward. Writing that out for meitnerium gives 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁷ 7s², which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d7 7s2 in plain text.

Everything up to Rn is the same as in that noble gas, so it is usually abbreviated to [Rn] 5f¹⁴ 6d⁷ 7s². The part outside the bracket is what does the chemistry.

Meitnerium ion charge

Meitnerium does not normally form ions. Its outer shell is already full, so there is nothing to gain by losing or gaining an electron.

Common questions

How many valence electrons does meitnerium have?

There is no single agreed answer for meitnerium. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 9, which is the group number. Check which convention your course uses before answering.

What is the electron configuration of meitnerium?

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d7 7s2, or [Rn] 5f14 6d7 7s2 written from the previous noble gas. Orbitals fill lowest energy first.

How many protons, electrons and neutrons does meitnerium have?

A neutral meitnerium atom has 109 protons and 109 electrons. Its standard atomic weight is 278, so the most common isotope has about 169 neutrons.

Nearby elements

• Iridium (Ir)above it in group 9
• Hassium (Hs)one place to its left
• Darmstadtium (Ds)one place to its right
• Cobalt (Co)same group, same valence count
• Rhodium (Rh)same group, same valence count

See the ionic charge of every element →