Arsenic

Symbol: As
Atomic number: 33
Category: metalloids
Group: 15
Period: 4
Block: p
Atomic weight: 74.92160 g/mol
Electrons per shell: 2, 8, 8, 5
CAS number: 7440-38-2
Phase: solid
Density: 5.727 kg/l (near room temperature)
Melting point: 1090 K (817C, 1503F)
Boiling point: 887 K (617C, 1137F)
Crystal structure: rhombohedral
Oxidation states: 5, 3, 1, -3
Electronegativity: 2.18 (Pauling scale)
Name's origin: zarnikh
Name's meaning: the Persian word for 'yellow orpiment' (mineral)
Facts:
- is a notoriously poisonous metalloid that has many allotropic forms: yellow (molecular non- metallic) and several black and grey forms (metalloids) are a few that are seen
- arsenic and its compounds are used as pesticides, herbicides, inse
- when ingested, arsenic disrupts ATP production through several mechanisms
- elemental arsenic and arsenic compounds are classified as 'toxic' and 'dangerous for the environment' in the European Union
- is more commonly found as arsenide and a
- a very popular murder chemical