Question

how is molecule co2 form by sharing of electrons what happen when co2 gas is dissolved in water

Answer 1

since CO2 is a light and hot gas it doesn't dissolve in water and moves upwards to the atmosphere

Answer 2

One reason a gas like carbon dioxide dissolves in water is its charge. CO2 is made up of one carbon atom and two oxygen atoms. The atoms share electrons, but they don't share those electrons evenly -- the oxygen ends of a CO2 molecule have a slight negative charge.