84 2 · 8 · 18 · 32 · 18 · 6

Polonium, Po, element 84

Metalloid· Period 6· Group 16· p-block

Configuration [Xe]4f145d106s26p4

Atomic weight
209Da
Phase
solid
Density
9.2g/cm³
Melting point
527.15K 254 °C
Boiling point
1,235.15K 962 °C
Electronegativity
2

Rare radioactive metallic element, belongs to group 16 of the periodic table. Over 30 known isotopes exist, the most of all elements. Po-209 has a half-life of 103 years. Possible uses in heating spacecraft. Discovered by Marie Curie in 1898 in a sample of pitchblende. Description from mendeleev.

Back to the table
The outermost shell: the valence electronsThe inner shellsThe nucleus One bead for each electron, on the ring of its shell, counted from the nucleus out. The rings turn at their own pace; the model is Bohr's picture of the atom, which places electrons in shells but not on true orbits.

Atomic properties

4 of 5 fields have a value for polonium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
209Da
Source: mendeleev
Electron configuration
[Xe]4f145d106s26p4
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p4
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 8 · 18 · 32 · 18 · 6
Source: Worked outfrom electron configuration

No data uncertainty of the atomic weight.

Screening of each subshell

Clementi's screening constants: how much of the nucleus's charge the other electrons hide from an electron in each subshell. What is left is the effective nuclear charge it feels.

SubshellScreening σEffective charge Z − σ
1s1.623282.3768
2s22.078261.9218
2p4.542879.4572
3s24.381359.6187
3p23.285160.7149
3d13.42870.572
4s35.478448.5216
4p36.332847.6672
4d36.332847.6672
4f37.841646.1584
5s51.97732.023
5p53.975530.0245
5d58.69625.304
6s67.669216.3308
6p69.779414.2206