1. Atomic Theory Review

2. Question 1 Which of the following statements is not associated with Dalton's Atomic Model? a)All matter is composed of very small, indestructible particles called atoms b) Atoms of the same element are identical and have a characteristic mass. c) Atoms of different elements are identical and have the same mass. d) Chemical reactions result from atoms of different elements combining to form compounds

3. Question 2 Which of the following best describes Dalton’s atomic theory? a)Matter consists of atoms containing positive and negative charges. b) Matter consists of atoms that contain a positive nucleus and electrons that move freely about the nucleus. c) Matter consists of atoms that contain a positive nucleus and electrons that move within different energy levels. d) Matter consists of atoms and all atoms of the same element are identical.

4. Question 3 Which of the following characteristics apply to Thomson’s atomic model? 1. A nucleus is located at the centre of the atom. 2. Electrons are scattered throughout the atom. 3. The nucleus is positively charged. 4. An atom may be divided. 5.Electrons are distributed among different energy levels. A) 1 and 3B) 1 and 4C) 2 and 4D) 3 and 5

5. Question 4 The following statements refer to atomic models. 1.There is a nucleus at the centre of the atom. 2.The nucleus is very small compared with the size of the entire atom. 3.The electrons are located in energy levels around the atom. Which of the following statements apply the Rutherford's atomic model? A)1 and 2 B)1, 2 and 3 C)1 and 3 D) 2 and 3

6. Question 5 Ernest Rutherford, a professor at McGill University in the early 1900s, performed an experiment in which he bombarded various metal sheets with alpha particles. Which of the following statements best describe the result of Rutherford's experiment on the deflection of alpha particles? 1. Most of the alpha particles were sharply deflected and bounced back at an angle greater than 90°. 2.Most of the alpha particles passed through the gold foil in a straight line. 3.All the alpha particles passed through the gold foil, but were slightly deflected. 4.A very small percentage of the alpha particles were sharply deflected and bounced back at an angle greater than 90°. A) 1 and 4B) 2 and 3C) 2 and 4D) 3 and 4

7. Question 6 Here is a representation of a molecule of water (H 2 O). Does it respect the principles behind Dalton’s atomic model? Explain your answer. H H O O H H

8. Question 7 **What conclusion did Thomson draw from each of the following observations? a)The cathode rays cause a small propeller inside the tube to turn. b)The cathode rays are attracted to the positive pole of an electric field.

9. Question 8 What type of radiation did Rutherford use for his research on atomic structure?

10. Question 9 Look at the illustration below. Each letter corresponds with an observation made by Rutherford. Describe each observation associated with each letter. A B C

11. Question 10 Which positively charged particle is found in the nucleus?

12. Question 11 What is the neutron’s function in the atom?

13. Question 11 Which particles of the atom account for most of its mass?

14. Question 12 Which is the lightest particle of the atom?