Astato (At)
Astato is the chemical element with atomic number 85 and symbol At. It is a semimetal in period 6, group 17, with a standard atomic weight of 210 u.
Dados essenciais
- Z
- 85
- Atomic weight
- 210 u no stable isotope
- Category
- semimetal
- State at 298 K
- Solid
- Occurrence
- from decay, radioactive
- Discovered
- 1940
- CAS
- 7440-68-8
Propriedades medidas
| Property | Value | Source |
|---|---|---|
| Electronegativity | 2.2 | National Center for Biotechnology Information (NIH) |
| Melting point | 575 K | National Center for Biotechnology Information (NIH) |
| Density stp | 7 g/cm³ | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 202 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 916.6 kJ/mol | National Center for Biotechnology Information (NIH) |
| Electron affinity | 270.2 kJ/mol | National Center for Biotechnology Information (NIH) |
Configuração eletrónica
- Noble gas notation
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁵
- Electrons per shell
- 2, 8, 18, 32, 18, 7