Arsenic
| Symbol | As |
| Atomic Number | 33 |
| Atomic Mass | 74.922 |
| Discovered by | Arsenic was discovered by Albertus Magnus |
What is Arsenic?
Arsenic, a chemical element placed in the nitrogen group of the periodic table that exists in both the gray and yellow crystalline forms.
Arsenic is present in three allotropic forms- black, yellow and gray. A silver-gray and brittle crystalline solid are the stable forms. It gets tarnished rapidly when comes in contact with air and at high temperatures by preparing a white cloud of arsenic trioxide. The metallic form of the element is brittle and it gets tarnished when oxidized to arsenic trioxide. Its non-metallic form is less reactive but easily dissolves when heated with strong oxidizing acids and alkalis.
Arsenic is a steel-gray, brittle solid with low thermal and electrical conductivity. There are some forms of elemental arsenic are metal-like and is best classified as a non-metal. Some other forms are also there but are not properly characterized. This element sublimes at 613 °C and it exists as As4 molecules. It is stable in dry air and in moist air it tends to become coated with a black oxide. The sublimed arsenic vapor heated in air to form an arsenic oxide.
Chemical Properties Of Arsenic
| Group | 15 | Melting point | Sublimes at 616°C, 1141°F, 889 K |
| Period | 4 | Boiling point | Sublimes at 616°C, 1141°F, 889 K |
| Block | p | Density (g cm−3) | 5.75 |
| Atomic number | 33 | Relative atomic mass | 74.922 |
| State at 20°C | Solid | Key isotopes | 75As |
| Electron configuration | [Ar] 3d104s24p3 | CAS number | 7440-38-2 |
| ChemSpider ID | 4514330 | ChemSpider is a free chemical structure database |
Uses Of Arsenic
- This element is mainly used in compounds and a smaller amount is used in alloys.
- It is also used to prepare lead shot in past and the amount used in these applications continues to decrease.
- Arsenic can easily get into the environment from such applications. Some amount is added to silicon and germanium to make transistors.
- Gallium arsenide, a compound of arsenic is used to make light-emitting diodes (LEDs). These LEDs produce the lighted numbers in the clock, watches, hand-held calculators and different other electronic devices.