Actinium (Ac): Properties, Uses and Facts in 3D
Actinium is element 89 on the periodic table, an actinide, so it is a metal. At room temperature it is a solid. Open it in the 3D Periodic Table to spin its tile, see its electron shells and read its story.
Explore in 3DActinium quick facts
| Atomic number | 89 |
|---|---|
| Symbol | Ac |
| Atomic mass | 227 |
| Category | Actinide |
| Series and period | Actinides, period 7 |
| Block | f-block |
| State at room temperature | Solid |
| Electron configuration | [Rn] 6d¹ 7s² |
| Electrons per shell | 2, 8, 18, 32, 18, 9, 2 |
| Discovered | 1899, Debierne |
What is actinium used for?
- Ac-225 targeted alpha therapy for cancer
- Neutron source (Ac-Be mixture)
- Scientific research
Interesting facts about actinium
- Actinium glows blue in the dark due to ionisation of surrounding air by its radiation
- Named after the Greek "aktinos" meaning ray. For its intense radioactivity
- Actinium-225 is a promising targeted alpha-particle therapy agent for treating cancer
Actinium was discovered in 1899 by Debierne in France.
Where actinium sits on the periodic table
Actinium is in the actinide series (period 7). Tap any element to open its page.
Other actinides
Actinium questions
What is the atomic number of actinium?
Actinium has atomic number 89, so every actinium atom has 89 protons in its nucleus. Its symbol is Ac and its atomic mass is 227.
Is actinium a metal?
Actinium is a metal. On the periodic table it is grouped as an actinide, found in the actinide series (period 7).
What is the electron configuration of actinium?
The electron configuration of actinium is [Rn] 6d¹ 7s². Its electrons sit in 7 shells: 2, 8, 18, 32, 18, 9, 2.
What is actinium used for?
Actinium is used for ac-225 targeted alpha therapy for cancer, neutron source (ac-be mixture) and scientific research.
Who discovered actinium?
Actinium was discovered in 1899 by Debierne in France.
The 3D Periodic Table is made by Julian Neagu, a solo founder in London, as part of VisionVix Simulators. It is free to use in the browser on desktop and phone, with no sign-up.