As pure elements. all of the halogens are diatomic molecular species. their melting points are: F2, 85 K, Cl2 239 K, Br2 332 K, and I2 457 K. using periodic table, how can i predict the molecular formula of elemental astatine. at the only radioactive element in this family. also predict whether it will be a solid, liquid, or gas at room temperature.
1 answer
it should have the same pattern; i.e. form diatomic molecules as by the other halogens. Molecules with more molecular weight have higher melting and boiling points due to the increase in electron density, which induces the magnitude of the dipole-dipole attraction.