Question

What is the reason behind the high surface tension of water?

Answer 1

I know it's something to do with its molecular structure

Answer 2

Surface tension is dependent on the interactions of molecules with their neighbours - these interactions are named "intermolecular forces", IMF.

What type of IMFs do water molecules have?

Answer 3

it is because of the hydrogen bond in water. H+ and OH- ions in H2O are partially polar and cause a relatively strong intermolecular force all over the liquid. this why it is liquid unlike its gaseous family members.