Elements
53

I

Iodine

Iodine (I) is a purple grey solid non metal. It has the atomic number 53 in the periodic table. It is located in Group 17, the Halogens. It has the symbol I.

Iodine was discovered in 1811 by Bernard Courtois when he was trying to extract potassium chloride from seaweed. By adding sulphuric acid a purple vapour was produced which formed into dark crystals. This was the element Iodine. Iodine’s name comes from the Greek word ‘Iodes’ meaning purple. Iodine easily forms compounds with group 1 and 2 elements usually uncoloured compounds and is one of the least reactive Halogens. Iodine is used in medicine, it is used as a disinfectant in surgery and also in the treatment of the thyroid. Silver iodide is used widely in photography and potassium iodide to clean wounds. In nature Iodine occurs mainly in seawater and seaweed a big source of Iodine for commercial use. It is located in Group 17 as a non metallic solid. It has a melting point of 113°c and a boiling point of 184°c.

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FAQ's

What is the Melting Point for Iodine?

Iodine has a Melting Point of 113.5°F, meaning at 113.5°F it will turn to a liquid.

What is the Boiling Point for Iodine?

Iodine has a Boiling Point of 184.35°F, meaning at 184.35°F it will turn to a Gas.

What is the Electronegativity of Iodine?

Iodine's Electronegativty is 2.66. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

What is the Heat of Vaporization of Iodine?

Iodine has a Heat of Vaporization of 20.752 kJ/mol.

Uses

Required in small amounts by humans. Once used as an antiseptic, but no longer due to its poisonous nature.

Sources

Occurs on land and in the sea in sodium and potassium compounds.

53
Protons
53
Electrons
74
Neutrons

I

Element Symbol
I
Atomic Weight
126.904
Atomic Number
53
State
Solid
Melting Point
Unknown
113.5
°C
Boiling Point
184.35
Unknown
°C
Heat of Vaporization
20.752
Unknown
kJ/mol
Crystal Structure
Orthorhombic
Thermoconductivity
0.00449
Unknown
W/cmK
Shells
2,8,18,18,7
Group
Halogen
Period
5
Block
P Block
Orbitals
[Kr] 4d10 5s2 5p5
Coefficient of Thermal Expansion
87 10^-6 K^-1
Covalent Radius
1.33 Å
Density at 293K
4.93 g/cm³
Electrical Conductivity
8.0e-16 10^6/cm ohm
First Ionization Potential
10.4513 V
Second Ionization Potential
19.131 V
Third Ionization Potential
33.0 V
Ionic Radius
2.20 (-1) Å
Oxydation States
(±1),5,7
Lattice Parameter
4.79 Å
Lattice Parameter 2
--
Lattice Parameter 3
--
Pronounced

EYE-eh-dine

Discovered by

Bernard Courtois

Discovery date

1811

Orbital configuration
2,8,18,18,7

Download the Periodic Table

Explore Other Halogens

18.998
9

F

Fluorine
210
85

At

Astatine
35.453
17

Cl

Chlorine
79.904
35

Br

Bromine
The halogens are located in group 17 (formally known as group VIIA) on the left of the noble gases on the periodic table. These five toxic, non-metallic elements make up group 17 and consist of: fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (As).
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