Question

Name the bond responsible for the force of attraction between water molecules and comment briefly on its effects on the properties of water?

Answer 1

Hydrogen bond....

Explanation:

Oxygen is the most ElectroNegative element in the Periodic Table (3.44), bar Fluorine (3.98)

This means that Oxygen pulls incredibly hard at electrons of other atoms. Hydrogen has an EN of "only" 2.20 so it's bound to be the losing side in this tug-of-war. Having said that, its EN is far higher than the other elements in group1, like Lithium and Sodium.
Whereas both Li and Na would immediately be stripped of their single electron (in the outer shell), H retains it. Hence it doesn't form Electrovalent bonds in `H_2O`, but covalent ones.

because of the boomerang shape of the `H_2O`-molecule:

(Picture courtesy of Benjah-bmm27 - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1997535)

the Oxygen atom (red Ball) tends to be `delta^-` (centre of the negative charge), both Hybrogen atoms tend to be `delta^+`.

They (the Hydrogens) therefore are attracted to the more negatively charged Oxygen atoms in other `H_2O`-molecules:

These hydrogen bonds are rather fleeting and short-lived of course (water is a fluid after all) but they DO have noticeable effects:

They are the cause of the high heat content and boiling point of water, and the reason why ice floats: (cold) water is more dense than ice, where the molecules are ordered in a Crystal.

The strong polar character of the `H_2O`-molecule also explains why salts like NaCl and a whole lot of other (polar) substances are readily dissolved by it....