O
Oxygen · element 8
Diatomic Nonmetal · Gas at room temperature
Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds (notably oxides) with most elements. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.
Key facts
Atomic mass
15.999 u
how heavy one atom is
Phase (room temp.)
Gas
Density
1.429 g/L
how tightly packed it is
Melting point
54.36 K (-219 °C)
when solid turns to liquid
Boiling point
90.188 K (-183 °C)
when liquid turns to gas
Period
2
its row in the periodic table
Group
16
its column in the periodic table
Block
P-block
the neighbourhood it lives in
Electronegativity
3.44
how strongly it pulls electrons
Electron configuration
[He] 2s2 2p4
where its electrons live
Shells
2 · 6
electrons in each layer, inside to out
Discovered by
Carl Wilhelm Scheele
who found it
Named by
Antoine Lavoisier
who gave it its name
Source: Wikipedia