11 2 · 8 · 1

Sodium, Na, element 11

Alkali metal· Period 3· Group 1· s-block

Configuration [Ne]3s1

Atomic weight
22.9898Da
Phase
solid
Density
0.97g/cm³
Melting point
370.944K 97.79 °C
Boiling point
1,156.09K 882.94 °C
Electronegativity
0.93

Soft silvery reactive element belonging to group 1 of the periodic table (alkali metals). It is highly reactive, oxidizing in air and reacting violently with water, forcing it to be kept under oil. It was first isolated by Humphrey Davy in 1807. 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 sodium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
22.98977Da
Source: mendeleev
Electron configuration
[Ne]3s1
Source: mendeleev
Uncertainty of the atomic weight
2×10−8Da
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s1
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 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
1s0.374110.6259
2s4.42866.5714
2p4.19826.8018
3s8.49262.5074