I
Iodine · element 53
Diatomic Nonmetal · Solid at room temperature
Iodine is a chemical element with symbol I and atomic number 53. The name is from Greek ἰοειδής ioeidēs, meaning violet or purple, due to the color of iodine vapor. Iodine and its compounds are primarily used in nutrition, and industrially in the production of acetic acid and certain polymers.
Key facts
Atomic mass
126.904473 u
how heavy one atom is
Phase (room temp.)
Solid
Density
4.933 g/cm³
how tightly packed it is
Melting point
386.85 K (114 °C)
when solid turns to liquid
Boiling point
457.4 K (184 °C)
when liquid turns to gas
Period
5
its row in the periodic table
Group
17
its column in the periodic table
Block
P-block
the neighbourhood it lives in
Electronegativity
2.66
how strongly it pulls electrons
Electron configuration
[Kr] 4d10 5s2 5p5
where its electrons live
Shells
2 · 8 · 18 · 18 · 7
electrons in each layer, inside to out
Discovered by
Bernard Courtois
who found it
Appearance
lustrous metallic gray, violet as a gas
what it looks like
Source: Wikipedia