See a chemistry test for an explanation of hydrogen bonding.
You are correct in saying that surface tension has to do with hydrogen bonding.
This means that hydrogen bonding can form at these two points for every repeat unit.
I could go into more detail about hydrogen bonding and so forth but that's the bottom line.
The water molecules are attracted to each other because of something called "hydrogen bonding".
Another way a force can be applied to a water molecule is by hydrogen bonding.
Water's structure is interesting due to the hydrogen bonding between molecules.
It is this hydrogen bonding that makes water from a liquid at room temperature.
Many of water's anomalous properties are due to very strong hydrogen bonding.
Thiols show little association by hydrogen bonding, with both water molecules and among themselves.