In an ice crystal, each water molecule is hydrogen bonded to _____ neighbouring molecules.

In an ice crystal, each water molecule is hydrogen bonded to four neighboring molecules. This arrangement forms a tetrahedral structure, which is crucial for the unique properties of ice.

When water freezes to form ice, the hydrogen bonds between the molecules become more stable and structured. Each water molecule (H2O) has two hydrogen atoms and one oxygen atom. The oxygen atom is highly electronegative, which creates polar covalent bonds within the molecule, leading to a partial positive charge near the hydrogen atoms and a partial negative charge near the oxygen atom. This polarity allows for the formation of hydrogen bonds between water molecules.

The tetrahedral arrangement means that each water molecule can interact with four adjacent hydrogen-bonded water molecules, creating a spacious crystal lattice that results in ice's lower density compared to liquid water. This is why ice floats on water, an essential feature for aquatic life, as it creates an insulating layer on bodies of water.

In summary, the hydrogen bonding in ice involves each water molecule creating four stable connections with others, highlighting the importance of hydrogen bonds in the solid state of water.