| How does hydrogen bonding occur between water molecules | Due to the polar water molecules interacting with each other. Oxygen is more negative and hydrogen is more positive. The more negative oxygen is attracted to the more hydrogen atom in the other molecules, vice versa, therefore creating a hydrogen bond |
| What are polar molecules | uneven distribution of electrons |
| Explain the thermal stability of water | - Water molecules have a high heat capacity due to the hydrogen bonds.
- Many hydrogen bonds between molecules = more energy needed to break bonds
- therefore, the temperature remains constant |
| Explain why ice is less dense | - As the water cools and freezes, hydrogen bonds fix the positions of the polar molecules slightly further apart than the average distance in a liquid state.
- therefore, water underneath stays liquid
- insulates the water underneath from the outside temperatures
- organisms are still able to move and allows nutrients to circulate |
| Explain how water is cohesive | Moves as one mass as molecules are attracted to each-other, therefore surface tension happens |
| Explain how water is a solvent | - As water molecules are polar, ions are able to interact with the water molecules
- this provides organisms with minerals and nutrients for growth |
