Ch 4 Study Guide

Ch 4 study guide Completion Complete each sentence or statement. 1. Unlike Democritus, Aristotle did not believe that matter was composed of tiny, indivisible ____________________. 2. John Dalton concluded that all the atoms of a single ____________________ have the same mass. 3. John Dalton observed that elements always combine in the same ratio to form a particular ____________________. 4. The subatomic particle that J.J. Thomson discovered has a(an) ____________________ charge. 5. Protons and ____________________ are found in the nucleus of an atom. 6. Neutrons and ____________________ have almost the same mass. 7. If element Q has 11 protons, its atomic ____________________ is 11. 8. The nuclei of isotopes contain different numbers of ____________________. 9. The _________________________ of an isotope is the sum of the number of protons and neutrons in its nucleus. 10. The difference between a sample of heavy water and regular water is that a hydrogen atom in heavy water has an extra ____________________. 11. In Bohr’s model of the atom, ____________________ move in fixed orbits around the nucleus. 12. When an atom gains or loses energy, some of its ____________________ may move between energy levels. 13. The moving blades of an airplane propeller provide an analogy for the electron ____________________ model. 14. The region in which an electron is most likely to be found is called a(an) ____________________. 15. When all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its ____________________ state. 16. An atom in which an electron has moved to a higher energy level is in a(an) ____________________ state. Short Answer 17. How did the results of J.J. Thomson’s experiments change how scientists thought about atoms? 18. What did Rutherford conclude about the location of positive charge in an atom? 19. Which of the three subatomic particles—proton, electron, or neutron—has the least mass? 20. If an atom has 32 protons and 38 neutrons, what is its mass number? 21. What scientific word comes from a Greek word meaning “uncut”? Which Greek philosopher first used the word to describe matter? 22. If an atom of an element has a mass number of 31 and 16 neutrons in its nucleus, what is the atomic number of the element?

23. If an atom of germanium has a mass number of 70 and an atomic number of 32, how many neutrons are in its nucleus? 24. Most calcium atoms have an atomic number of 20 and a mass number of 40, but some calcium atoms have a mass number of 48. What word could you use to describe these two kinds of calcium atoms? 25. In the nucleus of an atom, there are 15 protons and 16 neutrons. What is the atomic number and mass number of this isotope? 26. What can scientists measure to provide evidence that electrons can move from one energy level to another? 27. What did Bohr’s model of the atom do that Rutherford’s model did not? 28. How does the electron cloud model of the atom represent the locations of electrons in atoms? 29. What is the maximum number of electrons that an atomic orbital can contain? 30. How does the state of atoms in a neon light change when light is emitted? Other

Figure 4-3 31. Analyzing Data What subatomic particles are represented in Figure 4-3? Assuming all the particles in the nucleus are visible, what are the atomic and mass numbers of the atom shown?