Polonium (Po)
Polonium is element 84, a metalloid in group 16, period 6. A neutral atom has 84 protons, 125 neutrons and 84 electrons, 6 of them valence electrons.
Metalloid- Atomic number
- 84
- Atomic mass
- 208.98 u
- Valence electrons
- 6
- Protons · neutrons
- 84 · 125
- Electrons per shell
- 2, 8, 18, 32, 18, 6
- At room temperature
- solid
Bohr model of polonium
The Bohr model draws polonium as a nucleus of 84 protons and 125 neutrons, with its 84 electrons on 6 circular shells: 2 in shell 1, 8 in shell 2, 18 in shell 3, 32 in shell 4, 18 in shell 5, 6 in shell 6. Press Build the atom to watch the shells fill from the inside out. The outer ring (the P shell) is dashed: the electrons there are the ones that take part in chemistry.
Real electrons don't travel in neat circles. They live in fuzzy orbitals, shown below, but the Bohr picture is the quickest way to count shells and valence electrons.
Electron configuration of polonium
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁴
Short form (noble gas notation): [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p⁴. The [Xe] stands for the electrons of xenon, the noble gas before it.
How many valence electrons does polonium have?
Polonium has 6 valence electrons.
Polonium is in group 16, and for groups 13–18 you subtract 10 from the group number: 16 − 10 = 6. It tends to share electrons in covalent bonds.
Protons, neutrons and electrons
| Protons | 84 | equal to the atomic number |
|---|---|---|
| Electrons | 84 | equal to the protons in a neutral atom |
| Neutrons | 125 | mass number 209 − 84 protons |
Atoms of the same element can have different numbers of neutrons (isotopes). The count above uses the rounded atomic mass, the way it's taught in class.
Polonium properties
| Symbol | Po |
|---|---|
| Category | Metalloid |
| Group · period · block | 16 · 6 · p |
| Atomic mass | 208.98 u |
| State at 25 °C | solid |
| Melting point | 527 K (254 °C, 489 °F) |
| Boiling point | 1,235 K (962 °C, 1,760 °F) |
| Density | 9.32 g/cm³ |
| Electronegativity (Pauling) | 2 |
| Atomic radius | 197 pm |
| First ionization energy | 8.417 eV |
| Electron affinity | 1.9 eV |
| Oxidation states | +4, +2 |
| Common ion charge | +4, +2 |
| Discovered | 1898 by Pierre Curie |
Where polonium sits on the periodic table
Group 16: Oxygen, Sulfur, Selenium, Tellurium, Livermorium.
Questions about polonium
How many valence electrons does polonium have?
Polonium has 6 valence electrons.
How many protons, neutrons and electrons does polonium have?
A neutral polonium atom has 84 protons and 84 electrons. Its most common form has about 125 neutrons (mass number 209 − 84 protons).
What is the electron configuration of polonium?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁴, written in short form as [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p⁴.
What does the Bohr model of polonium look like?
A nucleus of 84 protons and 125 neutrons, circled by 6 electron shells holding 2, 8, 18, 32, 18, 6 electrons.
What is the atomic number of polonium?
84. The atomic number is the number of protons in the nucleus, and it is what makes an atom polonium.