88 2 · 8 · 18 · 32 · 18 · 8 · 2

Radium, Ra, element 88

Alkaline earth metal· Period 7· Group 2· s-block

Configuration [Rn]7s2

Atomic weight
226Da
Phase
solid
Density
5g/cm³
Melting point
969.15K 696 °C
Boiling point
2,010K 1,737 °C
Electronegativity
0.9

Radioactive metallic transuranic element, belongs to group 2 of the periodic table. Most stable isotope, Ra-226 has a half-life of 1602 years, which decays into radon. Isolated from pitchblende in 1898 Marie and Pierre Curie. 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 radium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
226Da
Source: mendeleev
Electron configuration
[Rn]7s2
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p67s2
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 8 · 18 · 32 · 18 · 8 · 2
Source: Worked outfrom electron configuration

No data uncertainty of the atomic weight.