Question

1 describe how water can be a liquid, solid, and gas.

Explanation:

Water exists in three states due to changes in temperature and pressure, which alter the motion and spacing of its H₂O molecules:

1. Solid (Ice): At temperatures ≤ 0°C (at standard pressure), water molecules slow down, form a rigid, hexagonal crystalline structure, and have fixed positions, giving ice a definite shape and volume.
2. Liquid (Water): Between 0°C and 100°C (at standard pressure), molecules have more kinetic energy, breaking some hydrogen bonds. They flow freely, taking the shape of their container but retaining a fixed volume.
3. Gas (Water Vapor): At temperatures ≥ 100°C (at standard pressure), or with reduced pressure at lower temperatures, molecules gain enough energy to break all hydrogen bonds. They spread out to fill any container, with no fixed shape or volume.

Answer:

Water exists as three states based on temperature/pressure and molecular behavior:

1. Solid (Ice): At ≤0°C (standard pressure), H₂O molecules form a rigid, ordered crystalline structure with fixed positions, creating a substance with a definite shape and volume.
2. Liquid (Liquid Water): Between 0°C and 100°C (standard pressure), molecules have moderate kinetic energy, allowing limited movement and flow; they take the shape of their container but maintain a fixed volume.
3. Gas (Water Vapor): At ≥100°C (standard pressure, or lower temperatures with reduced pressure), molecules gain high kinetic energy, break all hydrogen bonds, and spread out to fill any container, having no fixed shape or volume.