Why Did Dalton Think Atoms Formed New Substances?
Answer Key of worksheet # 1
Democritus Proposes the Atom
1. The word atom comes from a Greek word that means indivisible
2. Which of the following statements is part of Democritus’s theory about atoms?
a. Atoms are the smallest piece of matter.
3. We know that Democritus was right about atoms. So why did people ignore Democritus’s ideas for such a long time?
Democritus’s ideas were ignored for a long time because he had no proof of the atoms existence.
Dalton Creates an Atomic Theory Based on Experiments
4. By conducting experiments and making observations, Dalton figured out that elements combine in random proportions because they’re made of individual atoms. False
5. Dalton’s theory states that atoms cannot be changed, created, or …show more content…
How did Dalton think atoms formed new substances?
Atoms can be separated, rearranged and combined to form new substances.
Thomson Finds Electrons in the Atom
Mark the following statements True or False.
8. In 1897, J. J. Thomson made a discovery that proved the first part of Dalton’s atomic theory was correct. True
9. Thomson discovered that there were small particles inside the atom. True
10. Thomson found that the electrically charged plates affected the direction of a cathode-ray tube beam. True
11. Thomson knew the beam was made of particles with a positive charge because it was pulled toward a positive charge. False
12. When you rub a balloon on your hair, your hair is attracted to the balloon because both the hair and the balloon have become electrically charged. True
13. The two types of charges are positive and neutral. False
14. Objects with the same charges attract each other. False
Circle the correct answer.
15. In Thomson’s “plum-pudding” model, electrons are NOT
c. collected together in the center of the atom.
Rutherford Opens an Atomic
16. Before his experiment, Rutherford expected the particles to deflect to the sides of the gold foil. False
17. Which of the following statements is NOT part of Rutherford’s revision of his former teacher’s atomic
Democritus Proposes the Atom
1. The word atom comes from a Greek word that means indivisible
2. Which of the following statements is part of Democritus’s theory about atoms?
a. Atoms are the smallest piece of matter.
3. We know that Democritus was right about atoms. So why did people ignore Democritus’s ideas for such a long time?
Democritus’s ideas were ignored for a long time because he had no proof of the atoms existence.
Dalton Creates an Atomic Theory Based on Experiments
4. By conducting experiments and making observations, Dalton figured out that elements combine in random proportions because they’re made of individual atoms. False
5. Dalton’s theory states that atoms cannot be changed, created, or …show more content…
How did Dalton think atoms formed new substances?
Atoms can be separated, rearranged and combined to form new substances.
Thomson Finds Electrons in the Atom
Mark the following statements True or False.
8. In 1897, J. J. Thomson made a discovery that proved the first part of Dalton’s atomic theory was correct. True
9. Thomson discovered that there were small particles inside the atom. True
10. Thomson found that the electrically charged plates affected the direction of a cathode-ray tube beam. True
11. Thomson knew the beam was made of particles with a positive charge because it was pulled toward a positive charge. False
12. When you rub a balloon on your hair, your hair is attracted to the balloon because both the hair and the balloon have become electrically charged. True
13. The two types of charges are positive and neutral. False
14. Objects with the same charges attract each other. False
Circle the correct answer.
15. In Thomson’s “plum-pudding” model, electrons are NOT
c. collected together in the center of the atom.
Rutherford Opens an Atomic
16. Before his experiment, Rutherford expected the particles to deflect to the sides of the gold foil. False
17. Which of the following statements is NOT part of Rutherford’s revision of his former teacher’s atomic