In the periodic table, the halogen atom is placed within the seventeenth organisation of the periodic table. The halogen factors shown in the organisation are Fluorine, Chlorine, Bromine, Iodine, Tennessine, and Astatine. Consequently, when an atom of a different element receives electrons from halogen atoms, the outer electron shell fills up with electrons. The two atoms, therefore, combine to form a stable compound due to the reason that the halogen atom does not have its outer electron shell full.  The major common instance of such salts may be the edible salt.

Overview of Halogen atoms

• Halogen includes any of the six nonmetallic elements that make up the 17th (group VII) time series. The elements of halogen are tennessine, chlorine, bromine, astatine, iodine, and fluorine.
• The chemical elements are called halogens because they all produce salts of the same substance, one cation and one anion, as evidenced by their names. Table salt, or sodium chloride, is the most famous synonym of sodium chloride.
• Halogen is found in the glaciers of the Earth’s crust in amounts of 0.00003 iodine, 0.00016 bromine, 0.031 chlorine, and 0.06 fluorine. It is also very reactive.
• Astatine and tennessine are not naturally occurring because they contain only short-lived radioactive isotopes.

Fluorine 

• Hydrofluoric acid, which consists of fluorine atoms, was first discovered in 1886. Fluorine’s symbol is F. Fluorine was first discovered as an element in 1886 by separating the atoms of hydrofluoric acid.
• In its diatomic molecule, fluorine (F2) is available in large quantities in the earth’s crust.
• The periodic table has the most electronegative element: fluorine.  Despite its smaller atomic diameter, fluorine has a constant oxidation state of -1, except for its unique diatomic state (in which it has a constant oxidation state of 0). At room temperature, its appearance is similar to that of an element present in a gaseous state, being yellow in colour.
•  Hydrofluoric acid (HF) is an acid formed when fluorine reacts excessively and at once with all factors except Noble gases. Since fluoride ions are primary, HF is a susceptible acid because fluoride ions are very electronegative (pH> 7).

Chlorine

• • The chlorine molecule can undergo a variety of oxidation states, including having various charges. This includes having the charge of one, having both negative and positive charges, and three, five, and seven, all having positive charges. 
  •  Due to the weakened bond between the chlorine atoms, the molecule of Cl2 seems like crude gasoline at room temperature.

• Chlorine even has two isotopes, chlorine-35 and chlorine-37. It is an element having two atoms of chlorine joined together by molecular forces.

• In ocean water, salt is formed when ions of chloride are formed as a result of chemical reactions between metals and chloride. 

Bromine 

• The color of bromine at room temperature ranges from a reddish-brown to a greyish-white. It has both negative and positive charges in state one and positive charges in states three, four, and five.
•  It is an element having two atoms of bromine joined together by molecular forces.
• In the year eighteen-twenty six, the element bromine was found.
• Bromide’s availability and toughness led to a dramatic growth in bromide production, which can be found as bromide salts. As with all halogens, bromine is extremely toxic and oxidising. Two isotopes of Br are present—79Br and 81Br, and it has higher reactivity than iodine but a lower reactivity than chlorine.
• The atomic number of the element bromine is 35.

Iodine

• • Iodine has the atomic quantity fifty-three and the symbol ‘I’. Iodine has oxidation states one, having both positive and negative charges, and five and seven, both having positive charges. 

• It is an element having two atoms of iodine joined together by molecular forces.

•  Iodide ions can be extracted from seawater using seaweed and sulfuric acid. It was discovered in 1811 by using seaweed and sulfuric acid. 
• Iodine is a violet solid at room temperature. It has one stable isotope: 127I. 
• Despite iodine’s lower solubility in water, positive iodides can also increase solubility if they are added to the solution.
• In the year eighteen- eleven, the element iodine was found. It was found using sulfuric acid and extracting from seaweed.
•  The production of thyroid hormones is an important function of iodine in the lives of living organisms.

Conclusion

Due to their high reactivity, the free halogen elements do not occur naturally. The outermost electron shell of each halogen atom contains seven valence electrons. Halogen is placed in the 17th group of the periodic table. Consequently, while a halogen atom can get hold of an electron from an atom of exceptional detail, the 2 atoms form a completely strong compound because the halogen atom’s outermost electron shell is then complete.