Difference Between Halogen and Xenon

Main Difference – Halogen vs Xenon

Halogens and Xenon are chemical elements that are included in group 7 and group 8 of the periodic table, respectively. Halogens are very reactive elements. But xenon is a less reactive element. Halogens are the chemical elements in the group 7 of the periodic table and include F, Cl, Br, I and At. They have varying physical and chemical properties. Xenon is a noble gas that is in the group 8 of the periodic table. It is generally unreactive, but it can undergo several chemical reactions under extreme conditions. The main difference between halogens and xenon is that halogens have a single unpaired electron in their outermost orbital whereas xenon has no unpaired electrons in its orbitals.

Key Areas Covered

1. What is Halogen
      – Definition, Properties, Reactions and their Uses
2. What is Xenon
      – Definition, Properties, Reactions and their Uses
3. What are the Similarities Between Halogen and Xenon
      – Outline of Common Features
4. What is the Difference Between Halogen and Xenon
      – Comparison of Key Differences

Key Terms: Electronegativity, Halogen, Inert, Noble Gas, Reactivity, Xenon

What is Halogen

Halogen is a term used to represent the chemical elements in the group 7 of the periodic table of elements. This group includes fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and Astatine (At). These 5 elements together are called halogens. They were given the name halogen because they all form sodium salts of similar properties such as sodium fluoride (NaF) and sodium chloride (NaCl).

In the group of halogens, all three states of matter can be observed at standard temperature and pressure. Fluorine and chlorine exist as gases; bromine exists as a liquid. Iodine exists in the solid form while Astatine is a radioactive element.

Figure 01: Halogens: chlorine gas, bromine liquid, and iodine solid (left to right)

There are patterns of varying the physical and chemical properties down the group of halogens in the periodic table. For example, the chemical reactivity will decrease down the group due to the increase of the atomic size. However, halogens are highly reactive because they all have electron configurations ending with ns²np⁵. Since they lack one electron in order to fill their outermost orbital, they react with atoms or ions to obtain this electron. Therefore, halogens can be found in ionic compounds as well as in covalent compounds. The electronegativity of halogens decreases down the group.

In nature, halogens are found as diatomic molecules. Fluorine is the most reactive element among halogen elements due to its small size and lack of one electron to complete the octet rule. All halogens are good oxidizing agents. This is because they can easily be reduced to –1 oxidation state by gaining an electron.

The color of each element in halogen group greatly vary from one another. Fluorine has a light greenish yellow color whereas chlorine is more greenish. Bromine is a dark brown liquid. Iodine is a dark violet solid. Fluorine can have only -1 and 0 oxidation states. But other elements of halogen group can have up to +7 oxidation state.

What is Xenon

Xenon is a noble gas that has the symbol Xe. The atomic number of xenon is 54. It is included in the p block of the periodic table and is in the group 8. Xenon atom is a very large atom compared to other noble gases. It exists as a monoatomic gas in the standard temperature and pressure conditions. The electron configuration of xenon is given as [Kr]4d¹⁰5s²5p⁶. Therefore, the outermost orbital of xenon is completely filled with electrons. It is very much stable and is less reactive.

One important characteristic of xenon is that it can form compounds under extreme conditions where most other noble gases cannot. For example, xenon can form halides by combining with halogens such as fluorine. Some of the fluorides that xenon can form are XeF₂, XeF₄ and XeF₆. They are covalent compounds.

In addition, xenon also forms oxides by hydrolysis. But xenon cannot directly react with molecular oxygen. This reaction includes the reaction between xenon fluorides and water to produce xenon oxides and hydrogen fluoride (HF).

XeF₆ + 3H₂O → XeO₃ + 6HF

Figure 2: A Xenon Head Lamp

The appearance of xenon can be explained as a colorless and odorless gas. One of the major applications of xenon includes using as a light source. This is because xenon can produce a beautiful blue light that is glowing when excited by electrical discharge. This concept is used in xenon lamps.

Similarities Between Halogen and Xenon

Both are included in the p block of the periodic table.
Both are nonmetals.

Definition

Halogen: Halogen refers to the chemical elements in the group 7 of the periodic table of elements.

Xenon: Xenon is a noble gas that has the symbol Xe.

Group in the Periodic Table

Halogen: Halogens are in the group 7 of the periodic table.

Xenon: Xenon is in the group 8 of the periodic table.

Reactivity

Halogen: Halogens are highly chemically reactive.

Xenon: Xenon is unreactive under normal conditions.

Electron Configuration

Halogen: The electron configuration of halogens is incomplete.

Xenon: The electron configuration of xenon is complete.

Conclusion

Halogens are very useful as oxidizing agents. They are very strong oxidizing agents due to their incomplete electron configurations. Xenon is an inert gas at standard temperature and pressure conditions. However, xenon can form compounds under special conditions. The main difference between halogens and xenon is that halogens have a single unpaired electron in their outermost orbital whereas xenon has no unpaired electrons in its orbitals.

References:

1.”Halogen Uses – Boundless Open Textbook.” Boundless. Boundless, 26 May 2016. Web. Available here. 13 Aug. 2017.
2.”Xenon – Element information, properties and uses | Periodic Table.” Royal Society of Chemistry – Advancing excellence in the chemical sciences. N.p., n.d. Web. Available here. 13 Aug. 2017.

Image Courtesy:

1. “Halogens” By W. Oelen – Science Made Alive: Chemistry/Elem – HalogensTransferred from en.wikipedia to Commons by User:ТимофейЛееСуда (CC BY-SA 3.0) via Commons Wikimedia
2. “Lincoln xenon headlamp” By Ford Motor Company from USA – 2009 Lincoln MKS (CC BY 2.0) via Commons Wikimedia