Chapter 4 Review 1-20

1. The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

• a. element
• b. atom
• c. electron
• d. molecule

2. Democritus thought that matter was made of tiny particles

• a. of earth, air, fire, and water.
• b. that could not be divided.
• c. that could be divided.
• d. that were all round and smooth.

3. If 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of element Y would combine with 14 grams of X to form the same compound?

• a. 7 grams
• b. 14 grams
• c. 21 grams
• d. 28 grams

4. According to John Dalton’s observations, when elements combine in a compound,

• a. the ratio of their masses is always the same.
• b. each element contributes an equal number of atoms.
• c. their volumes are always equal.
• d. their masses are always equal.

5. Which of the following is NOT part of John Dalton’s atomic theory?

• a. All elements are composed of atoms.
• b. All atoms of the same element have the same mass.
• c. Atoms contain subatomic particles.
• d. A compound contains atoms of more than one element.

6. Which of the following most accurately represents John Dalton’s model of the atom?

• a. a tiny, solid sphere with an unpredictable mass for a given element
• b. a hollow sphere with a dense nucleus
• c. a tiny, solid sphere with a predictable mass for a given element
• d. a sphere that is hollow throughout

7. J. J. Thomson’s experiments provided evidence that an atom

• a. is the smallest particle of matter.
• b. contains negatively charged particles.
• c. has a negative charge.
• d. has a positive charge.

8. The diagram in Figure 4-1 shows the results of Rutherford’s gold foil experiment. What caused some of the alpha particles to bounce straight back from the gold foil?

• a. electrons in the gold atoms
• b. negative charges in the gold atoms
• c. other alpha particles
• d. nuclei in the gold atoms

9. Rutherford’s gold foil experiment provided evidence for which of the following statements?

• a. Negative and positive charges are spread evenly throughout an atom.
• b. Alpha particles have a positive charge.
• c. Gold is not as dense as previously thought.
• d. There is a dense, positively charged mass in the center of an atom.

10. Who provided evidence for the existence of a nucleus in an atom?

• a. John Dalton
• b. J. J. Thomson
• c. Democritus
• d. Ernest Rutherford