Tb
Lanthanide
Terbium
Z 65A 159mass 158.93
Atomic model
tap a particleEvery nucleon is drawn individually — 65 protons and 94 neutrons packed into the nucleus, with 65 electrons on shells outside.
65+1
Protons
Set the element — change this and it becomes a different atom.
940
Neutrons
Change only these and you get a different isotope of the same element.
65−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 159 (65 p + 94 n)
- Electron shells
- 2 · 8 · 18 · 27 · 8 · 2
- Valence shell
- 2 electrons
- Atomic mass
- 158.93 u
Stability
Terbium has no measured radioactive isotope in this lab — its nuclei are stable, so decay must be shown as an illustration.
Open the decay lab