Trends In Chemical Reactivity Of Halogens

Halogens are found in Group 17 (Halogens) of the periodic table. Halogens are extremely reactive non-metals with properties strikingly similar to those of metals. Halogens are members of group 17 of the periodic table (In Greek, the word ‘halo’ represents salt, while ‘genes’ means producing, and so collectively, it stands for salt-producing). The components in concern include chlorine, fluorine, bromine, astatine, and iodine.

Furthermore, no other group of a contemporary periodic table has a connection to this degree. Both physical and chemical parameters show a consistent progression. Astatine seems to be the only radioactive element under this category. Halogens have seven electrons in their outermost shells (ns2np5) and thus are one electron of the noble gas structure closest to them. The oxidation state that an element exhibit determines its reactivity and chemical characteristics.

Halogens List

Either there are 5 or 6 halogens, based on who we believe. Halogens include fluorine, chlorine, bromine, iodine, as well as astatine. Tennessine, element 117, may share specific properties with other factors. Despite being in the same column and a group like the other halogens in the periodic table, many scientists think element 117 acts somewhat like a metalloid. So little of that has been created, and it’s a matter of speculation rather than statistical results.

• Fluorine
• Bromine
• Chlorine
• Astatine
• Iodine
• Tennessine 

Uses of Halogen

Living creatures contain lighter halogens. The four components are fluorine, chlorine, bromine, and iodine. 

• Chlorine and iodine are needed for human nutrition. However, the other elements may be necessary for trace levels.
• Halogens play a vital role in disinfection. Water and surfaces were disinfected with chlorine and bromine. 
• Because of the strong chemical reactivity of halogens, these elements are significant components of various bleaches.
•  Incandescent lamps utilise halogens to shine at a higher temperature with a whiter hue. 
• The halogen elements are essential medicinal ingredients because they help drugs penetrate tissues.

Looking Closely at the Components

Fluorine has the atomic number 9 and the symbol F. Pure fluorine is just a light yellowish gas at room temperature and pressure. However, because the element is now so reactive, this is only found in compounds. 

• Chlorine, with atomic number 17 and also the sign Cl, is a chemical substance. In normal conditions, chlorine is just a greenish-yellow gas.
• Bromine, abbreviated as Br, is a chemical element with Br’s symbol. It is a liquid at ambient temperatures and pressure.
• Iodine is the 53rd element of the periodic table, with the sign I. It is solid in typical circumstances.
• At is the symbol for astatine, and its atomic number is 85. It is also the rare naturally occurring substance in the Earth’s crust. Astatine, which would be a radioactive substance, has no stable isotopes.

Halogens’ Chemical Properties

As usual, halogens have a -1 oxidation state, although bromine, chlorine, and iodine have +1, +3, +5, +7 oxidation levels, respectively. When halogens are combined with highly electronegative oxygen or fluorine atoms, they can increase oxidation. Halogens are, therefore, highly reactive, so thus frequently create halides when they react with metal and non-metal.

As we move farther from the group, the halogens’ reactivity declines. In addition, halogens efficiently receive electrons because they lack one electron and form an octet. As a result, they have significant oxidising properties. The most powerful oxidising agent in the halogen family is fluorine; it also oxidises other halide ions in the solution.

Electronegativity Trends Across Halogens within Periodic Table

Electronegativity refers to an atom’s ability to attract an additional electron. Particles with high electronegativities can attract more electrons and gain electrons from those other atoms when creating chemical bonds. Low-electronegativities atoms are much more inclined to share electrons in a bond.

The electronegativity of an atom in such a chemical bond can be described as its ability to attract its shared electron pair itself. Halogens seem to be the most electronegative of all other elements in a cycle due to their small atomic volume and high nuclear energy. With just a rise in atomic size, its non-metallic or electronegative character decreases significantly, moving down a group.

The electronegativity of halogens could be calculated by using the following.

F = 4, Br = 2.8, Cl = 3, I = 2.5.

Why are Chlorines’ Electron Affinity Greater than Fluorines?

This is owing to fluorine’s condensed composition. Because chlorine does have a bigger atomic size, this could hold additional electrons, but fluorine’s electrons are closer together. As a result, fluorine’s packed electrons screen its actual nuclear charge, resulting in a decreased electron affinity.

Pseudo Halogens: What Would They Mean?

Pseudo halogens were generated when two or more P block elements of a periodic table having a unit negative charge merged to create a group. A cyanide group, for instance, is a combination of carbon and nitrogen with a unit-negative order. They’re called pseudohalogens since they generate covalent compounds or complexes in the periodic table, just like halogens. They vary from halogens in that, unlike halogens, these can polymerise because their complexes aren’t paramagnetic.

Conclusion

Halogens are highly reactive, and in large quantities, these could be damaging or deadly to living species. The strong electronegativity and effective nuclear charge cause this chemical reactivity of halogens. Halogens can acquire an electron by interacting using atoms of other elements. Fluorine is among the elements that show the most chemical reactivity in halogens.