37 2 · 8 · 18 · 8 · 1

Rubidium, Rb, element 37

Alkali metal· Period 5· Group 1· s-block

Configuration [Kr]5s1

Atomic weight
85.4678Da
Phase
solid
Density
1.53g/cm³
Melting point
312.45K 39.3 °C
Boiling point
961.15K 688 °C
Electronegativity
0.82

Soft silvery metallic element, belongs to group 1 of the periodic table. Rb-97, the naturally occurring isotope, is radioactive. It is highly reactive, with properties similar to other elements in group 1, like igniting spontaneously in air. Discovered spectroscopically in 1861 by W. Bunsen and G.R. Kirchoff. 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 rubidium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
85.4678Da
Source: mendeleev
Electron configuration
[Kr]5s1
Source: mendeleev
Uncertainty of the atomic weight
3×10−4Da
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s23p63d104s24p65s1
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 8 · 18 · 8 · 1
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.

SubshellScreening σEffective charge Z − σ
1s0.792236.2078
2s9.843227.1568
2p3.961233.0388
3s15.157321.8427
3p15.696721.3033
3d15.320821.6792
4s24.61212.388
4p26.119210.8808
5s32.01554.9845