Zainab Bt. Ariffin (90286)

1. CHANGES IN THE STATE OF MATTER Presented by: Zainab Bt. Ariffin (90286)

2. MATTER Matter is anything that occupies space and has mass. Matter is made up of tiny and discrete particles. These particles are: Atom. Molecule. Ion.

3. Matter exist in 3 states :- Liquid Solid Gas

4. Solid • . The particles are packed closely together in an orderly manner. • A solid has a • fixed volume • and shape. • A solid cannot • be compressed There are strong forces between the particles. The particles can only vibrate and rotate about their fixed positions.

5. Liquid • A liquid cannot • be compress • easily. A liquid has a fixed volume. It does not have a fixed shape but takes the shape of the container. • The particles are • held together by • strong forces but • weaker than the • forces in a solid. The particles are closely together but not in orderly arrangement The particles can vibrate, rotate and move throughout the liquid. They collide against each other

6. Gas The particles are very far apart from each other and in a random motion. • A gas does not • have a fixed • shape or volume. • A gas can • be compressed • easily. There are weak forces between the particles. The particles can vibrate, rotate and move freely. The rate of collision is greater than the rate of collision in a liquid.

7. Inter-conversion of the state of matter GAS Sublimation evaporation Sublimation condensation freezing LIQUID SOLID melting Key : :heating :cooling

8. The change in heat affects the kinetic energy of particles decreasing heat solid liquid gas increasing heat

9. Melting point • When solid is heated , the particles in the solid gain kinetic energy and vibrate more vigorously. • The particles vibrate faster as the temperature increases until the energythey gained is able to overcome the forces that hold them at their fixed position.

10. At this point, the solid become liquid • This process called melting • The temperature at which this happen is called the melting point.

11. Freezing Point • When a liquid is cooled, the particles in the liquid lose energy and move slower. • As the temperature continues to drop, the particles continue to lose more energy until they do not have enough energy to move freely.

12. At this point, the liquid changes into the solid • This process is called freezing • The temperature at which this happen is called freezing point

13. The heating curve Temperature (°c) D Melting point B C A Time (min)

14. At point A :- • The matter exists as solid. When the solid is heated, heat energy is absorbed. • This cause the particles to gain kinetic energyandvibrate faster. • This is why the temperature increases.

15. At point B to C :- • The solid begin to melt • Both liquid and solid are present • During the melting process , the temperature of the matter does not rise, even though heating continues. • The temperature remain constant because the heat energy absorb by the particles is used to overcome the forces between particles so that the solid can turn into liquid. • This constant temperature is the melting point of the matter.

16. At point C and D :- • All the solid has melted and change to the liquid • From point C to Point D, the particles in liquid matter absorb heat energy and move faster. • The temperature increases from point C to D.

17. The cooling curve Temperature (°c) E Freezing point F G H Time (min)

18. At point E to F : • The particles in the liquid lose their kinetic energy • They move slower as the temperature decrease

19. At point F :- • The liquid matter begins to freeze. • Its temperature remains constant because the heat loss to the surroundings is exactly balanced by the heat energy liberated as the particles attract one another to form solid

20. At point G to H:- • The solid is cooled • The particles in the solid vibrate slower as the temperature decreases