Correct Answer:
D. All of these
The correct answer is All of these because solid, liquid, and gas represent the three classical states of matter commonly observed in nature.
- Step 1 (States of Matter): Matter is defined as anything that possesses mass and occupies physical space. Depending on the thermal energy and pressure applied to its atoms or molecules, it can easily change forms.
- Step 2 (The Classical Phases): A Solid has a fixed volume and shape; a Liquid maintains a fixed volume but conforms to the shape of its container; a Gas expands freely to fill both the volume and shape of its container. Therefore, all three are valid states.
- Incorrect Options:
- Liquid is incorrect on its own because it overlooks the fact that matter can also freeze into solids or vaporize into gaseous phases.
- Solid is incorrect on its own because it fails to represent the flowing liquid or dispersed gaseous states matter can acquire.
- Gas is incorrect on its own because it ignores the condensed phase states that substances manifest under standard conditions.