Antimony (Sb)
[Kr] 4d¹⁰ 5s² 5p³. 3 unpaired electrons, period 5, group 15, 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.
SbAntimony, Z = 51, 121.76 u
[Kr] 4d10 5s2 5p3
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p³
- Blockp block
- Period5
- Group15
- Valence5
- Unpaired3
- MagneticPara
Last electron 5p
- n5shell
- l1p subshell
- m+1orbital
- s+½spin up
Step by step
- Antimony has 51 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p³.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p³.
- Replace the krypton core with [Kr]: [Kr] 4d¹⁰ 5s² 5p³.
Antimony (Sb): the numbers
| Atomic number | 51 |
|---|---|
| Atomic mass | 121.76 u |
| Period | 5 |
| Group | 15 |
| Block | p block |
| Valence electrons | 5 |
| Unpaired electrons | 3 |
| Magnetic | paramagnetic |
| Last electron | 5p: n = 5, l = 1, m = +1, s = +1/2 |
Antimony (Sb): quick answers
What is the electronic configuration of antimony?
Antimony has 51 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p³, or [Kr] 4d¹⁰ 5s² 5p³ in short.
How many unpaired electrons does antimony have?
Antimony has 3 unpaired electrons, 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 antimony?
The last electron goes into 5p: n = 5, l = 1, m = +1, s = +1/2. Orbitals fill from m = −l up, spin +½ first.