Particle Model of Matter

3. A state of matter where particles are far apart and move freely in all directions.
6. The process where a solid changes directly into a gas without becoming a liquid.
7. The energy that particles have due to their movement.
8. The process where a gas turns into a liquid when it is cooled.
10. A law stating that the pressure of a gas is inversely proportional to its volume at a constant temperature.
11. A tiny piece of matter, such as an atom or molecule, that makes up all materials.
13. The energy required to change 1 kg of a substance from liquid to gas without changing its temperature.
15. The mass of a substance per unit volume, calculated as mass divided by volume.
17. The amount of energy required to raise the temperature of 1 kg of a substance by 1°C.
18. The amount of matter in an object, measured in kilograms (kg).
20. The process where a liquid changes to a gas throughout the substance at its boiling point.
21. A measure of the average kinetic energy of the particles in a substance.
23. The energy required to change 1 kg of a substance from solid to liquid without changing its temperature.
25. The force exerted per unit area by the particles in a gas.

1. The process where particles at the surface of a liquid gain enough energy to become gas.
2. The process of changing from a liquid to a solid.
4. The amount of energy required to change the state of 1 kg of a substance without changing its temperature.
5. The three main forms of matter: solid, liquid, and gas.
9. A state of matter where particles are tightly packed in a fixed shape and position.
12. A state of matter where particles are close together but can move past each other, allowing the substance to flow.
14. The total energy stored in the particles of a substance due to their movement and positions.
16. The change in total energy when a substance is heated or cooled, affecting its temperature or state.
19. The process of changing from a solid to a liquid at the melting point.
22. The amount of space an object or substance takes up, measured in cubic meters (m³).
24. A material that slows down the transfer of thermal energy.