Understanding the scientific rationale behind Arsenic's position in the periodic table:
Belongs to Group 15 because it has 5 valence electrons (4s² 4p³).
Belongs to Period 4 because its outermost electrons occupy n=4.
Belongs to the p-block because its differentiating electrons occupy 4p orbitals.
Classified as a metalloid due to intermediate metallic sheen and semi-metallic electrical conductivity.
Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.
Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.
Neutral ground state configuration. Valence electrons: 5.
Found in minerals arsenopyrite (FeAsS), realgar (As₄S₄), and orpiment (As₂S₃), and volcanic hydrothermal veins.
From Greek 'arsenikon', referring to yellow orpiment mineral pigment
Extremely toxic carcinogen; chronic exposure via contaminated groundwater causes arsenicosis, skin lesions, and organ failure.