Arsenic occurs in minerals.
Uses and research
Some arsenic compounds are used in specialized semiconductor materials.
Between familiar metals and nonmetals
This guide classifies it as a metalloid, a useful label for elements with some properties between typical metals and nonmetals. The exact membership can vary between references. A category label alone does not determine conductivity, hardness or every other property: structure, temperature and composition also matter.
What the atomic number tells us
Arsenic has atomic number 33. This is the number of protons in its nucleus. A neutral atom also has 33 electrons. Losing or gaining electrons makes an ion; it does not change the element unless the proton count changes.
The model's rings help count electrons by shell. They are not actual circular paths. A model of one atom and the properties of a whole material are different levels of description.
Temperature and state
25°C: Solid
Illustrative particle motion: sizes, distances and speeds are not to scale. Particles represent atoms or molecules.
← CoolHeat →
Sublimation (approx.) 616°C
At 1 atmosphere arsenic sublimes without a liquid phase.
Pure element at 1 atmosphere. Image conditions are explained in captions. Pictures do not change with temperature.