Elements
17

Cl

Chlorine

Chlorine (Cl) exists as a yellow green gas with a pungent smell. It has the atomic number 17 in the periodic table and belongs in Group 17, the Halogens. It is a non metal with the symbol Cl.

Chlorine much like other Halogens has antiseptic properties. It is used in swimming pools commonly and also making drinking water safe by killing bacteria. It is also used in the production of many plastics such as PVC and also the production of insecticides and solvents. Chlorine was first produced by Carl Wilhelm Scheele in 1774 when he reacted Manganese dioxide with hydrochloric acid, at the time he did not know the name of these chemicals and instead named them as the alchemical forms of pyrolusite and spiritus salis. It took many years before Humphrey Davy concluded that the new gas discovered was a new element, he named it Chlorine after the Greek ‘Chloros’ meaning yellow green. It is located in Group 17 as a non metal yellow gas with a pungent smell familiar with swimming pools at room temperature. It has a melting point of -155°c and a boiling point of -100°c. Chlorine gas has been used in the production of many solvents but it was not until 1915 during World War 1 that the german army used chlorine gas as a chemical weapon.

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FAQ's

What is the Melting Point for Chlorine?

Chlorine has a Melting Point of -103°F, meaning at -103°F it will turn to a liquid.

What is the Boiling Point for Chlorine?

Chlorine has a Boiling Point of -34°F, meaning at -34°F it will turn to a Gas.

What is the Electronegativity of Chlorine?

Chlorine's Electronegativty is 3.16. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

What is the Heat of Vaporization of Chlorine?

Chlorine has a Heat of Vaporization of 10.2 kJ/mol.

Uses

Used in water purification, bleaches, acids and many, many other compounds such as chlorofluorocarbons (CFC).

Sources

Salt (sodium chloride, NaCl) is its most common compound. Commercial quantities are produced by electrolysis of aqueous sodium chloride (seawater or brine from salt mines).

17
Protons
17
Electrons
18
Neutrons

Cl

Element Symbol
Cl
Atomic Weight
35.453
Atomic Number
17
State
Gas
Melting Point
Unknown
-103
°C
Boiling Point
-34
Unknown
°C
Heat of Vaporization
10.2
Unknown
kJ/mol
Crystal Structure
Orthorhombic
Thermoconductivity
0.000089
Unknown
W/cmK
Shells
2,8,7
Group
Halogen
Period
3
Block
P Block
Orbitals
[Ne] 3s2 3p5
Coefficient of Thermal Expansion
--
Covalent Radius
0.99 Å
Density at 293K
0.003214 g/cm³
Electrical Conductivity
--
First Ionization Potential
12.9676 V
Second Ionization Potential
23.81 V
Third Ionization Potential
39.611 V
Ionic Radius
1.81 (-1) Å
Oxydation States
(±1),3,5,7
Lattice Parameter
--
Lattice Parameter 2
7.661 Å
Lattice Parameter 3
--
Pronounced

KLOR-een

Discovered by

Carl Wilhelm Scheele

Discovery date

1774

Orbital configuration
2,8,7

Download the Periodic Table

Explore Other Halogens

18.998
9

F

Fluorine
79.904
35

Br

Bromine
126.904
53

I

Iodine
210
85

At

Astatine
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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