At normal atmospheric pressure arsenic does not melt when heated, it sublimes. i.e. when heated, arsenic undergoes a phase change directly from solid to gas.
The melting point quoted above is for gray arsenic under a pressure of 28 atmospheres.
Arsenic is a chemical element with symbol As and atomic number 33.
Arsenic appears in three allotropic forms: yellow, black and grey; the stable form is a silver-gray, brittle crystalline solid. It tarnishes rapidly in air, and at high temperatures burns forming a white cloud of arsenic trioxide. Arsenic is a member of group Va of the periodic table, which combines readily with many elements.
The metallic form is brittle, tharnishes and when heated it rapidly oxidizes to arsenic trioxide, which has a garlic odor. The non metallic form is less reactive but will dissolve when heated with strong oxidizing acids and alkalis.
Arsenic is an element that exists naturally in the Earth’s crust. Small amounts of arsenic are found in some rock, soil, water, and air. When arsenic combines with other chemical elements, it creates compounds, or chemical mixtures. When people come in contact with arsenic in the environment, it is often with compounds.