Chlorine (Cl) – Periodic Table [Element Information & More]

Chlorine element (Cl) is in group 17 and period 3 of a periodic table. Chlorine is in the p-block and it is classified as a halogen group element on the periodic table.

There is a lot more information related to chlorine which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

• Chlorine element (Information Table)
• Chlorine element in Periodic table
• Facts about Chlorine
• Properties of Chlorine
• Uses of Chlorine

Chlorine Element (Information Table)

The important data related to chlorine element is given in the table below.

Appearance of chlorine	Pale yellow-green gas
Atomic number of chlorine	17
Symbol of chlorine	Cl
Atomic mass of chlorine	35.45 u
Protons, Neutrons & Electrons in chlorine	Protons: 17, Neutrons: 18, Electrons: 17
State of chlorine (at STP)	Gas
Group number of chlorine in periodic table	17
Period number of chlorine in periodic table	3
Block of chlorine in periodic table	p-block
Category of chlorine	Nonmetals (halogens)
Bohr model or Electrons per shell or Electrons arrangement in chlorine	2, 8, 7
Electron configuration of chlorine	[Ne] 3s2 3p5
Orbital diagram of chlorine
Valence electrons in chlorine	7
Electronegativity of chlorine (on pauling scale)	3.16
Atomic radius of chlorine (van der Waals radius)	175 picometers
Density of chlorine	3.214 g/L
1st ionization energy of chlorine	12.968 eV
Main isotope of chlorine	35Cl and 37Cl
Melting point of chlorine (Cl2)	171.6 K or -101.5 °C or -105.7 °F
Boiling point of chlorine (Cl2)	239.11 K or -34.04 °C or -29.27 °F
Crystal structure of chlorine	Orthorhombic
Discovery of chlorine	By Carl Wilhelm Scheele in 1774

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Chlorine element in Periodic table

The Chlorine element (Cl) has the atomic number 17 and is located in group 17 and period 3. Chlorine is a nonmetal and it is classified as a halogen element.

Click on above elements in the periodic table to see their information.

Facts about chlorine

Here are a few interesting facts about chlorine element.

1. The chlorine element is given its name from the Greek word “khloros” which means “greenish-yellow” (which is the appearance of the chlorine gas).
2. Chlorine is the 3^rd most abundant element present in the ocean.
3. Chlorine is the 21^st most abundant element present in the earth’s crust.
4. Sea water has a very large amount of chlorine (present in NaCl in seawater).
5. Chlorine is also present in the human body.
6. The chlorine always exists as a diatomic molecule (i.e Cl₂).
7. We intake chlorine from food (i.e table salt (NaCl)). Inhaling a pure chlorine gas is toxic for the human body.

Properties of chlorine

Here is a list of some physical properties and chemical properties of chlorine.

Physical properties of chlorine

• Chlorine gas has a pale yellow-green color appearance.
• Chlorine gas has a strong smell.
• The atomic mass of chlorine is 35.45 u and its density is 3.214 g/L.
• The melting point and boiling point of chlorine (Cl₂) is 171.6 K and 239.11 K respectively.

Chemical properties of chlorine

• Chlorine shows chemical reaction with many elements because it has higher electronegativity and high electron affinity.
• Chlorine is a reactive nonmetal and hence it is always found with other compounds.
• Chlorine does not show any reaction with lighter noble gases, because the noble gases are chemically inert.
• Chlorine forms a white mist when it reacts with ammonia (NH₃).
• Chlorine gas is liberated on electrolysis of salt water.
• Chlorine is a nonflammable gas and it is non explosive in nature.
• Chlorine is also added to drinking water to kill bacteria and microorganisms.

Uses of chlorine

Here are some uses of the chlorine element.

• Chlorine was once used as a chemical weapon which can burn the skin.
• Chlorine is also used in manufacturing of medicines, disinfectants as well as insecticides.
• The paper industries, plastic industries as well as dyes industries also used chlorine.
• Polyvinyl Chloride (PVC) is a polymer that has chlorine in it.

External resources:

1. Chlorine. (2022, April 5). American Chemistry Council. https://www.americanchemistry.com/industry-groups/chlorine
2. The Facts About Chlorine. (2005, May 1). The Facts About Chlorine. https://www.health.ny.gov/environmental/emergency/chemical_terrorism/chlorine_tech.htm
3. Chlorine – Wikipedia. (2008, July 10). Chlorine – Wikipedia. https://en.wikipedia.org/wiki/Chlorine
4. Chlorine | Cl | ChemSpider. (n.d.). Chlorine | Cl | ChemSpider. http://www.chemspider.com/Chemical-Structure.4514529.html?rid=25ffff43-68be-497e-8aba-1967c86cbe75&page_num=0
5. Atomic Data for Chlorine (Cl). (n.d.). Atomic Data for Chlorine (Cl). https://physics.nist.gov/PhysRefData/Handbook/Tables/chlorinetable1.htm
6. Periodic Table of Elements: Los Alamos National Laboratory. (n.d.). Periodic Table of Elements: Los Alamos National Laboratory. https://periodic.lanl.gov/17.shtml
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