33 2 · 8 · 18 · 5

Arsenic, As, element 33

Metalloid· Period 4· Group 15· p-block

Configuration [Ar]3d¹⁰4s²4p³

Atomic weight: 74.9216Da
Phase: solid
Density: 5.75g/cm³
Melting point: 1,090.15K 817 °C
Boiling point: 889.15K 616 °C
Electronegativity: 2.18

Metalloid element of group 15. There are three allotropes, yellow, black, and grey. Reacts with halogens, concentrated oxidizing acids and hot alkalis. Albertus Magnus is believed to have been the first to isolate the element in 1250. 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 arsenic

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.: 74.92159Da; Source: mendeleev
Electron configuration: [Ar]3d¹⁰4s²4p³; Source: mendeleev
Uncertainty of the atomic weight: 6×10⁻⁶Da; Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p³; Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.: 2 · 8 · 18 · 5; 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	0.7217	32.2783
2s	8.873	24.127
2p	3.9264	29.0736
3s	14.4045	18.5955
3p	15.1503	17.8497
3d	15.6216	17.3784
4s	24.056	8.944
4p	25.5508	7.4492