The key difference between chlorine fluorine and astatine is that chlorine is a pale yellow-green gas, and fluorine is a very pale-colored gas, whereas astatine is a radioactive chemical element that rarely occurs in nature.
Chlorine, fluorine, and astatine are three members of the halogen group. Halogens are reactive elements that consist of diatomic molecules and are present on the left of the noble gases on the periodic table of elements.
What is Chlorine?
Chlorine is a gaseous compound having the chemical formula Cl2. It appears as a pale yellow-green gas at room temperature and pressure. Chlorine gas acts as an extremely reactive agent, so it is a strong oxidizing agent. Furthermore, this gas has a pungent, irritating odor that is similar to bleach. The IUPAC name of this gas is “molecular chlorine.”
The molar mass of chlorine gas is 70.9 g/mol. The two chlorine atoms in this molecule are covalently bonded to each other. We call it a “diatomic gas” because there are two atoms linked to each other per molecule. The inhalation of this gas is toxic, and it is also an irritant to the eye. The gas is slightly soluble in water and can liquefy at -35◦C. However, we can readily liquefy this gas by applying an appropriate pressure at room temperature. Moreover, this gas is not flammable, but it can support combustion.
More importantly, this gas is toxic if we inhale it. The chlorine gas is heavier than normal air. Therefore, it tends to collect in lower areas of the atmosphere. It’s melting and boiling points are -101°C and -35°C, respectively. It is useful as a disinfectant in many industries, for water treatment, to make war gases, etc.
What is Fluorine?
Fluorine is a chemical element denoted by F. It is a halogen (17th group) in the 2nd period of the periodic table. The atomic number of fluorine is 9; thus, it has nine protons and nine electrons. Its electron configuration is written as 1s2 2s2 2p5. Since the p sublevel should have 6 electrons to obtain Neon, noble gas electron configuration, fluorine has the ability to attract an electron. According to the Pauling scale, Fluorine has the highest electronegativity in the periodic table, which is about 4.
The atomic mass of fluorine is 18.9984 amu. At room temperature, fluorine exists as a diatomic molecule (F2). F2 is a pale yellow-greenish color gas and has a melting point of -219 °C and a boiling point of -188 °C. Among isotopes of fluorine, F-17 is not a stable isotope, and it has a half-life of 1.8 hours. But F-19 is a stable isotope. The abundance of F-19 on earth is 100%. Fluorine can oxidize oxygen, and its oxidation state is -1.
Fluorine gas is denser than air, and it can also be liquefied and solidified. It is highly reactive; this is due to its high electronegativity and weak fluorine-fluorine bond. Moreover, the reactions of this chemical species with most of the other molecules are fast. Because of the reactivity, it is not found as a free element.
What is Astatine?
Astatine is a highly radioactive element that belongs to the group of halogens. It has the chemical symbol At and atomic number 85. We can describe astatine as the rarest naturally occurring chemical element in the Earth’s crust. It occurs only as a decay product of various heavier elements. Typically, all of the isotopes of astatine are short-lived species astatine-210 being the most stable among them. Therefore, the bulk properties of this chemical element are not known certainly.
Astatine most likely tends to have a dark and lustrous appearance. It can possibly be a semiconductor or a metal. There are several anionic species of astatine that show the properties of the compounds of iodine. Sometimes it can show metallic characteristics and can show similarities to silver.
What is the Difference Between Chlorine Fluorine and Astatine?
The key difference between chlorine fluorine and astatine is that chlorine appears as a pale yellow-green gas and fluorine appears as a very pale-colored gas whereas astatine is a radioactive chemical element that rarely occurs in nature.
The below infographic presents the differences between chlorine fluorine and astatine in tabular form for side-by-side comparison.
Summary – Chlorine vs Fluorine vs Astatine
Chlorine, fluorine, and astatine are three members of the halogen group. The key difference between chlorine, fluorine, and astatine is that chlorine appears as a pale yellow-green gas and fluorine appears as a very pale-colored gas whereas astatine is a radioactive chemical element that rarely occurs in nature.
1. “Water Treatment Solutions.” Lenntech Water Treatment & Purification.