Explanations:
The cohesive nature of water is due to the hydrogen bond that is present between the water molecules.
In water molecules, the oxygen atom tends to be more electronegative than the hydrogen atom causing the hydrogen atom to gain a slight positive charge during their interaction.
Since the the oxygen atom only has 2 lone electrons that are not involved in bonding, hence atoms in water molecule get attracted towards the lone pairs present in oxygen atoms leading to an attraction force known as hydrogen bonding.