36 2 · 8 · 18 · 8

Krypton, Kr, element 36

Noble gas· Period 4· Group 18· p-block

Configuration [Ar]3d¹⁰4s²4p⁶

Atomic weight: 83.798Da
Phase: gas
Density: 0.003425g/cm³
Melting point: 115.78K -157.37 °C
Boiling point: 119.735K -153.41 °C
Electronegativity: 3

Colorless gaseous element, belongs to the noble gases. Occurs in the air, 0.0001% by volume. It can be extracted from liquid air by fractional distillation. Generally not isolated, but used with other inert gases in fluorescent lamps. Five natural isotopes, and five radioactive isotopes. Kr-85, the most stable radioactive isotope, has a half-life of 10.76 years and is produced in fission reactors. Practically inert, though known to form compounds with Fluorine. 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

5 of 5 fields have a value for krypton

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.: 83.798Da; Source: mendeleev
Electron configuration: [Ar]3d¹⁰4s²4p⁶; Source: mendeleev
Uncertainty of the atomic weight: 0.002Da; Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶; Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.: 2 · 8 · 18 · 8; Source: Worked outfrom electron configuration

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.

Subshell	Screening σ	Effective charge Z − σ
1s	0.7684	35.2316
2s	9.602	26.398
2p	3.953	32.047
3s	14.9673	21.0327
3p	15.5658	20.4342
3d	15.3741	20.6259
4s	24.6844	11.3156
4p	26.2308	9.7692