Astatine (At)
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵. 1 unpaired electron, period 6, group 17, p block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
AtAstatine, Z = 85, [210] u
[Xe] 4f14 5d10 6s2 6p5
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁵
- Blockp block
- Period6
- Group17
- Valence7
- Unpaired1
- MagneticPara
Last electron 6p
- n6shell
- l1p subshell
- m0orbital
- s−½spin down
Step by step
- Astatine has 85 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁵.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁵.
- Replace the xenon core with [Xe]: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵.
Astatine (At): the numbers
| Atomic number | 85 |
|---|---|
| Atomic mass | [210] u |
| Period | 6 |
| Group | 17 |
| Block | p block |
| Valence electrons | 7 |
| Unpaired electrons | 1 |
| Magnetic | paramagnetic |
| Last electron | 6p: n = 6, l = 1, m = 0, s = −1/2 |
Astatine (At): quick answers
What is the electronic configuration of astatine?
Astatine has 85 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁵, or [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵ in short.
How many unpaired electrons does astatine have?
Astatine has 1 unpaired electron, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of astatine?
The last electron goes into 6p: n = 6, l = 1, m = 0, s = −1/2. Orbitals fill from m = −l up, spin +½ first.