18
Ar
Argon
Noble gas period 3 group 18 p-block discovered: 1894
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 18
- Atomic mass
- 39.9 a.m.u.
- Electron configuration
- [Ne]3s2 3p6
- Atomic radius
- 188 pm
- Ionization energy
- 15.760 eV
- Oxidation states
- 0
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Gas
- Melting point
- 83.8 K (-189,35 °C)
- Boiling point
- 87.3 K (-185,85 °C)
- Density
- 0.0017837 g/cm³
Materials about this element
-
5.4. Аргоноиды
Book page
Лайнус Полинг, Питер Полинг - Химия
Первый элемент в периодической таблице, водород, химически активен и образует огромное число соединений.