72 2 · 8 · 18 · 32 · 10 · 2

Hafnium, Hf, element 72

Transition metal· Period 6· Group 4· d-block

Configuration [Xe]4f145d26s2

Atomic weight
178.49Da
Phase
solid
Density
13.3g/cm³
Melting point
2,506.15K 2,233 °C
Boiling point
4,873.15K 4,600 °C
Electronegativity
1.3

Silvery lustrous metallic transition element. Used in tungsten alloys in filaments and electrodes, also acts as a neutron absorber. First reported by Urbain in 1911, existence was finally established in 1923 by D. Coster, G.C. de Hevesy in 1923. 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 hafnium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
178.49Da
Source: mendeleev
Electron configuration
[Xe]4f145d26s2
Source: mendeleev
Uncertainty of the atomic weight
0.02Da
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s23p63d104s24p64d104f145s25p65d26s2
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 8 · 18 · 32 · 10 · 2
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
1s1.398470.6016
2s18.810253.1898
2p4.401267.5988
3s21.688550.3115
3p21.016850.9832
3d13.570258.4298
4s33.022838.9772
4p34.070437.9296
4d36.47635.524
4f39.790432.2096
5s50.16721.833
5p52.41519.585
5d55.380516.6195
6s62.83569.1644