33
As
74.922
Arsenic (As)
Element 33 · Period 4 · Group 15
metalloid
solid at room temp
p-block
About Arsenic
Toxic metalloid historically used as poison. Used in semiconductors and wood preservatives.
Physical Properties
Atomic Mass
74.922 u
State at 25°C
Solid
Melting Point
817 °C
Boiling Point
614 °C
Density
5.776 g/cm³
Magnetism
Diamagnetic
Atomic Properties
Electron Configuration
[Ar] 3d¹⁰ 4s² 4p³
Electron Shells
2, 8, 18, 5
Electronegativity
2.18
Atomic Radius
114 pm
Ionization Energy
947 kJ/mol
Oxidation States
-3, +3, +5
Discovery & History
Discovered By
Albertus Magnus
Discovery Year
1250
Named By
Albertus Magnus
Name origin: Greek: arsenikon (yellow orpiment)
Frequently Asked Questions
- Is Arsenic a metal, nonmetal, or metalloid?
- Arsenic is classified as a metalloid.
- What state is Arsenic in at room temperature?
- Arsenic is a solid at standard room temperature (25°C).
- What is the atomic mass of Arsenic?
- Arsenic has an atomic mass of 74.922 atomic mass units (u).
- Who discovered Arsenic?
- Arsenic was discovered by Albertus Magnus in 1250.
- Where is Arsenic on the periodic table?
- Arsenic is element number 33, located in period 4 and group 15.