Write the name of radioactive halogen?

Hint: This element occurs very rarely in nature. It is a heavy element with six shells in its atom. It has a dark and lustrous appearance. Chemically, its anionic form resembles that of iodine.

Complete step by step answer:
- Astatine is an element belonging to the sixth period and group 17 of the modern periodic table. It is represented by the symbol At and has an atomic number = 85.
- Its electronic configuration is given as - \[[Xe]4{{f}^{14}}5{{d}^{10}}6{{s}^{2}}6{{p}^{5}}\].
- Astatine has an unstable combination of protons and neutrons and has no stable isotopes. Till now, its thirty-two isotopes have been discovered. The main isotopes of Astatine include – Astatine- 209, 210 and 211. Astatine-210 has a half-life of 8.1 hours and is the longest-lived isotope.
- Astatine is mainly obtained by synthesizing it through nuclear reactions.
- It is made by bombarding bismuth with accelerated alpha particles (helium nuclei) to yield astatine-211 and neutrons.
- It is also obtained by heating astatine - containing cyclotron. In this process, after heating it is cooled during which astatine volatilizes and condenses in a cold trap.

Additional Information: Astatine is taken from the Greek word “astatos”, which means “unstable.”

Note: Group 17 of the periodic table contains the elements known as halogens. These elements contain 7 electrons in its valence shell. Halogens other than Astatine are not radioactive in nature.