-
30. Describe two ways that an ion forms from an atom.
by gaining or losing electrons
-
31. State the number of electrons either lost or gained in the following ion: Br-
gain of 1 electron
-
31. State the number of electrons either lost or gained in the following ion: Na+
loss of one electron
-
31. State the number of electrons either lost or gained in the following ion: As3-
gain of 3 electrons
-
31. State the number of electrons either lost or gained in the following ion: Ca2+
loss of 2 electrons
-
31. State the number of electrons either lost or gained in the following ion: Cu+
loss of 1 electron
-
31. State the number of electrons either lost or gained in the following ion: H-
gain of 1 electron
-
32. Anion or cation and name it? Br-
bromide, anion
-
32. Anion or cation and name it? Na+
sodium, cation
-
32. Anion or cation and name it? As3-
arsenide, anion
-
32. Anion or cation and name it? Ca2+
calcium, cation
-
32. Anion or cation and name it? Cu+
copper, cation
-
32. Anion or cation and name it? H-
hydride, anion
-
33. Define valence electrons.
electrons in the highest occupied energy level
-
34. How many electrons does each atom have and what group is it in? nitrogen
7, 5A
-
34. How many electrons does each atom have and what group is it in? lithium
3, 1A
-
34. How many electrons does each atom have and what group is it in? phosphorus
15, 5A
-
34. How many electrons does each atom have and what group is it in? barium
56, 2A
-
34. How many electrons does each atom have and what group is it in? bromine
35, 7A
-
34. How many electrons does each atom have and what group is it in? carbon
6, 4A
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35. Write electron dot structures for: Cl
-
35. Write electron dot structures for: S
-
35. Write electron dot structures for: Al
-
35. Write electron dot structures for: Li
-
36. How many electrons must each atom lose to attain a noble-gas electron configuration?
a. Ca b. Al c. Li d. Ba
-
37. Write the formula for the ion formed when each of the following elements loses its valence electrons.
- a. aluminum b. lithium c. barium
- d. potassium e. calcium f. strontium
-
38. Why do nonmetals tend to form anions when they react to form compounds?
-
39. What is the formula of the ion formed when the following elements gain or lose valence electrons and attain noble-gas configurations?
- a. sulfur b. sodium
- c. fluorine d. phosphorus
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40. How many electrons must be gained by each of the following atoms to achieve a stable electron configuration?
a. N b. S c. Cl d. P
-
41. Which of the following pair of atoms would you expect to combine chemically to form an ionic compound? Why?
- a. Li and S b. O and S
- c. Al and O d. F and Cl
- e. I and K f. H and N
- 42. Identify the kinds of ions that form each ionic compound.
- a. calcium fluoride, CaF2
- b. aluminum bromide, AlBr3
- c. lithium oxide, Li2O
- d. aluminum sulfide, Al2S3
- e. potassium nitrite, K3N
-
43. Explain why ionic compounds are electrically neutral.
-
44. Which of the following pairs of elements will not form ionic compounds? Why not?
- a. sulfur and oxygen b. sodium and calcium
- c. sodium and sulfur d. oxygen and chloride
-
45. Write the formula for the ions in the following compounds.
- a. KCl b. BaSO4
- c. MgBr2 d. Li2CO3
-
46. Most ionic substances are brittle. Why?
-
47. Explain why molten MgCl2 does conduct an electric current although crystalline MgCl2 does not.
-
48. Explain briefly why metals are good conductors of electricity.
-
49. Name the three crystal arrangements of closely packed metal atoms. Give an example of a metal that crystallizes in each arrangement.
-
50. Name some alloys that you have used or seen today.
-
51. Explain why the properties of all steel are not identical.
-
55. In terms of electrons, why does a cation have a positive charge?
-
57. The spheres below represent the relative diameters of atoms or ions. Rearrange the sequences in a. and b. so the relative sizes of the particles correspond to the increasing size of the particles as shown in the illustration.
-
60. The atoms of the noble gas elements are stable. Explain.
-
62. Write electron configurations for these atoms and ions, and comment on the result.
- a. Ar b. Cl-
- c. S2- d. P3-
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