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chlorine

Chlorine is the 17th Element of Periodic table with atomic number 17, atomic weight 35.453. Chlorine symbol Cl, has a Base Centered Orthorhombic structure and Yellow color. Chlorine is a Halogens element. It is part of group 17 (fluorine family). Know everything about Chlorine Facts, Properties, Electronic configuration, Atomic and Crystal Structure.

History of Chlorine

The element Chlorine was discovered by W. Scheele in year 1774 in Sweden. Chlorine was first isolated by W. Scheele in 1774. Chlorine derived its name from the Greek word chloros, meaning ‘greenish yellow’.

Obtained it from hydrochloric acid, but thought it was an oxide. Only in 1808 did Humphry Davy recognize it as an element.

How to Locate Chlorine on Periodic Table

Elements are arranged in periodic table by atomic number, number of protons in the nucleus which is same as number of electrons. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 17 to find Chlorine on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Chlorine on periodic table look for cross section of group 17 and period 3 in the modern periodic table.

Chlorine Facts

Name
Silicon
Atomic Symbol
Cl
Atomic Number
17
Phase
Gas
Atomic Weight
35.453
Colour
Yellow
Classification
Halogens
Group in Periodic Table
17
Group Name
fluorine family
Block in Periodic Table
p-block
Period in Periodic Table
3
Electronic Configuration
[Ne] 3s2 3p5
Melting Point
171.6 K
Boiling Point
239.11 K
Electronic Shell Structure
[2, 8, 7]
CAS Number
CAS7782-50-5

Chlorine Atomic Structure and Orbital Properties

Chlorine atoms have 17 electrons and the electronic shell structure is [2, 8, 7] with Atomic Term Symbol (Quantum Numbers) 2P3/2.

Element Properties

Atomic Number
17
Number of Protons
17
Mass Number
35
Number of Neutrons
17
Shell structure (Electrons per energy level)
[2, 8, 7]
Electron Configuration
[Ne] 3s2 3p5
Valence Electrons
3s2 3p5
Valence (Valency)
5
Oxidation State
-1, 1, 2, 3, 4, 5, 6, 7
Atomic Term Symbol (Quantum Numbers)
2P3/2

Atomic Structure of Chlorine

Atomic Radius
79 pm (0.79 Ã…)
Atomic Volume
22.4129 cm3/mol
Covalent Radius
99 pm (0.99 Ã…)
Van der Waals Radius
175 pm
Neutron Cross Section
35.3
Neutron Mass Absorption
0.033

Ground State Electronic Configuration of Chlorine - neutral Chlorine atom

Abbreviated electronic configuration of Chlorine

The ground state abbreviated electronic configuration of Neutral Chlorine atom is [Ne] 3s2 3p5. The portion of Chlorine configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ne]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 3s2 3p5, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Chlorine

Complete ground state electronic configuration for the Chlorine atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p5

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

Atomic Spectrum of Chlorine

Chlorine spectrum

Chlorine Chemical Properties : Chlorine Ionization Energies and electron affinity

ElectronAffinity
349 kJ/mol
Valence
5
Electronegativity
3.16

Use of Chlorine

Chlorine is one of the most useful element in the World. Mostly used in:

  • Water. Chlorine chemistry helps keep drinking water and swimming pools safe.
  • Household Disinfectant.
  • Food.
  • Healthcare.
  • Energy and Environment.
  • Advanced Technology.
  • Building and Construction.
  • Defense and Law Enforcement.
106. Seaborgium [Sg]