Arsenic
METALLOID
Bohr Model: Electrons arranged in energy shells around the nucleus.
Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. Arsenic is a metalloid.
Quick Facts
Atomic Number 33
Period 4
Group 15
Phase Solid
Appearance metallic grey
About Metalloids
Metalloids have properties intermediate between metals and nonmetals. They often act as semi-conductors, making them essential for electronics.
History
Discovered By Bronze Age
Named By Unknown
Physical Properties
Atomic Mass 74.9215956
Density 5.727 g/L
Molar Heat 24.64 J/(mol·K)
Phase Transition (Melting & Boiling Points)
Arsenic phase transition data is unavailable.
Atomic Properties
Electron Config [Ar] 3d10 4s2 4p3
Electronegativity 2.18
Electron Affinity 77.65 kJ/mol
Ionization Energy 947 kJ/mol
Orbital Filling Diagram
This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule.
Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down.
Electrons fill lower energy levels first and occupy orbitals singly before pairing.
Photograph
External Resources
Study Guide
Atomic Number
The number of protons in the nucleus, which defines the element.
Atomic Mass
The average mass of an atom, including protons and neutrons.
Electronegativity
A measure of how strongly an atom attracts electrons in a bond.
Ionization Energy
The energy required to remove an electron from an atom.
Electron Config
The arrangement of electrons in the atom's energy shells.