Bromine molecules have covalent bonding. Bromine molecule is stabilized by weak intermolecular forces of attraction such as van der Waals forces of attraction. van der Waals forces are result of creation of instantaneous dipoles caused by the uneven distribution of the electron cloud. The weak intermolecular forces of attraction account for the lower melting point of bromine.
Melting point is dependent on the intermolecular forces which means the bonds between the molecules of bromine as it is a simple molecular structure the intermolecular bonds of bromine are weak bcz they are weak vandervaal forces thats why Bromines melting point is low..In short when intermolecular bomds are weak the M.P is lower
When excess of carbon dioxide is passed in lime water, calcium carbonate is converted to calcium bicarbonate which is soluble, hence the milkiness due to calcium carbonate disappears.
