Arsenic

Atomic Number: 33
Symbol: As
Atomic Mass: 74.92 u
Number of Neutrons: 42
Melting Point: 816.8°C
Boiling Point: 613°C
Electrons per shell: 2.8.18.5
Electron configuration: [Ar] 3d¹⁰ 4s² 4p³

---

Arsenic is the 33rd element in the periodic table and it is a metalliod. It is a silver-gray or white element. It occurs in many minerals and ores in combination with sulfur and other metals. Arsenic is found in the earth but also in the atmosphere. One third of the arsenic in the atmosphere comes from natural causes, such as volcanoes, and the rest is man made. You might have noticed that arsenic has a higher melting point than the boiling point and that is correct. This is because arsenic change phases directly from a solid to a gas under normal atmospheric pressure. Arsenic was discovered in 1250, by Albertus Magnus, a German philosopher and alchemist. Though, many used arsenic before this discovery.

Previous Element  Next Element