Question

F2 and cl2 are gases br2 is a liquid and i2 is a solid at room temperature because

Answer 1

The London dispersion forces become progressively stronger. At a low enough temperature the molecules will all be solids. At a high enough temperature they will all be gases. It is only at temperatures between -7 °C and 59 °C that fluorine and chlorine are gases, bromine is a solid, and iodine is a solid.

Answer 2

Down the group, the London dispersion forces increase progressively thus I₂ is solid at room temperature

• The existence of F₂ and other halogens in different physical states depends on the strength of the London forces present in the molecule.
• In F₂ and Cl₂, the atoms are held closer and more tightly to the nuclei due to the small atomic radius, thus the London dispersion forces are weak because of which they exist in the gaseous state.
• Down the group, as atomic radius increases, the electrons are less strongly attracted towards the nucleus causing the London dispersion forces to become stronger, thus Br₂ exists as a liquid at room temperature.
• I₂ exists as a solid as it has the strongest amount of London dispersion forces since it has a very large atomic radius and electrons can easily get distorted since they are not close to the nucleus.