Mt
Transition metal
Meitnerium
Z 109A 278mass 278
Atomic model
tap a particleEvery nucleon is drawn individually — 109 protons and 169 neutrons packed into the nucleus, with 109 electrons on shells outside.
109+1
Protons
Set the element — change this and it becomes a different atom.
1690
Neutrons
Change only these and you get a different isotope of the same element.
109−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 278 (109 p + 169 n)
- Electron shells
- 2 · 8 · 18 · 32 · 32 · 15 · 2
- Valence shell
- 2 electrons
- Atomic mass
- 278 u
Stability
Meitnerium has no measured radioactive isotope in this lab — its nuclei are stable, so decay must be shown as an illustration.
Open the decay lab