PowerPoint for grade 8 science observation.pptx

grade 8 science obsevation

1. Let’s play!

2. OBJECTIVE: Evaluate the importance of cathode ray tube in discovering electrons. describe Thomson's Model of the Atom, including the presence of electrons within a positively charged sphere. 2

3. V.S Raisins Bread Loaf Bread

4. When the balloon is rubbed, electrons are transferred from the material to the balloon, giving the balloon a negative charge. This creates an imbalance of charges, as the material loses electrons and becomes positively charged. This charge imbalance causes the balloon to attract small pieces of paper, which are neutral and are therefore attracted to the negatively charged balloon. Additionally, when the negatively charged balloon is brought close to hair, it can cause the hair strands to repel each other, making the hair stand on end. Explanation: 5

5. Who is J.j Thomson?

6. J.J. Thomson was a British physicist born in 1856 He is best known for his discovery of the electron through the experiment. Thomson conducted experiments with cathode ray tubes , observing the behavior of cathode rays . His real name is Joseph John Thomson. He proposed the Plum-pudding Model of Atomic Structure.

7. Tanong ko, Sagot mo !

8. Who discovered the electron? J.J THOMSON/ JOSEPH JOHN THOMSON 9

9. JOSEPH JOHN THOMSON 10 What is the complete name of j.j Thomson?

10. CATHODE RAY TUBE 11 What DID HE USE IN HIS EXPERIMENT?

11. PLUM-PUDDING MODEL 12 What DO YOU CALL THE ATOMIC MODEL HE PROPOSED?

12. How did Thomson discover the electron using the cathode ray tube?

13. J.J. Thomson discovered the electron through his experiments with cathode ray tubes . A cathode ray produced when a stream of particles traveled from the negatively charged cathode to the positively charged anode The cathode ray tube is a sealed glass tube containing a partially evacuated chamber with two metal electrodes : a negatively charged cathode and a positively charged anode .

14. Thomson concluded that cathode rays were composed of negatively charged particles, which he named electrons . Thomson introduce electric and magnetic fields into the path of the cathode rays. He observed that the rays were deflected by both electric and magnetic fields. Th e deflection of the cathode rays was always towards the positive plate in an electric field and away from the north pole of a magnet . This indicated that cathode rays carried a negative charge .

15. Tanong ko, Sagot mo !

16. a sealed glass tube containing a partially evacuated chamber with two metal electrodes 17 What IS CATHODE RAY TUBE?

17. negatively charged cathode and a positively charged anode. 18 What ARE THE TWO METAL ELECTRODES?

18. when a stream of particles traveled from the negatively charged cathode to the positively charged anode 19 HOW CATHODE RAY PRODUCED?

19. DEFLECTED 20 WHAT HAPPEN TO CATHODE RAY WHEN THOMSON INTRODUCE ELECTRIC AND MAGNETIC FIELD??

20. Thomson proposed a model of the atom known as the “Plum- Pudding" model.

21. THOMSON’S ATOMIC model

22. 23 What is plum-pudding model?

23. Plum-pudding model 24 In this model, the atom was envisioned as a positively charged sphere with embedded negatively charged electrons. A proposed atomic model by J.J. Thomson in the early 20th century. T he positive charge was spread uniformly throughout the atom, like the cake portion of a plum pudding, and the negatively charged electrons were thought to be dispersed within the positively charged sphere, like the plums in the pudding.

24. Plum-pudding model 25 Thomson proposed this model based on his discovery of the electron and his understanding that atoms contained both positive and negative charges. And later on this model, was revised and replaced by more refined atomic models, such as Ernest Rutherford's nuclear model and Niels Bohr's planetary model , which better explained the distribution of charge within the atom and the arrangement of electrons in specific energy levels or orbits

25. Activity time!

26. INSTRUCTION: Group yourself into 5 groups Within your group make your own model of Plum-pudding model using the materials. Make it more creative. You can have this as your basis on your model criteria: CREATIVITY=50% RELEVANCE=20% CLEANLINESS=20% CORRECT LABELING=10%

27. WRAP UP!

28. QUESTION AND CLARIFFICATION