Which general statement does NOT apply to metals?
21. Which general statement does NOT apply to metals? (1 point)
Most metals are ductile.
Most metals are malleable.
Most metals are brittle.
Most metals are good conductors of electric current.
22. Among the alkali metals, the tendency to react with other substances (1 point)
does not vary among the members of the group.
increases from top to bottom within the group.
varies in an unpredictable way within the group.
decreases from top to bottom within the group.
23. Study the electron dot diagrams for lithium, carbon, fluorine, and neon in Figure 6-1. Choose the statement that correctly identifies the most stable of the elements.
Lithium is the most stable element because it has to lose only one electron to achieve a stable configuration.
Carbon is the most stable element because it can form four bonds.
Fluorine is the most stable element because it has to gain only one electron to achieve a stable configuration.
Neon is the most stable element because its highest occupied energy level is filled.
24. The formation of an ionic bond involves the
transfer of electrons.
transfer of neutrons.
transfer of protons.
sharing of electrons.
25. In a polar covalent bond,
electrons are shared equally between atoms.
a cation is bonded to an anion.
electrons are transferred between atoms.
electrons are not shared equally between atoms.
26. Beryllium, Be, and chlorine, Cl, form a binary ionic compound with a one-to-two ratio of beryllium ions to chloride ions. The formula for the compound is
Be2Cl.
BeCl.
BeCl2.
Be2Cl2.
27. When magnesium carbonate, MgCO2, reacts with nitric acid, HNO3, magnesium nitrate and carbonic acid form. Carbonic acid then breaks down into water and carbon dioxide. Which two types of reactions take place in this process?27. double-replacement and decomposition
28. In terms of energy, how would you classify the following chemical reaction?
2Cu + O2 -> 2CuO + 315 kJ
endothermic
exothermic
both endothermic and exothermic
neither endothermic nor exothermic
29. A log is burning in a fireplace. If the amount of oxygen reaching the log is decreased, which of the following statements is true?
The reaction rate increases.
The reaction rate decreases.
The reaction rate remains the same.
The reaction rate depends only on the temperature.
30. A student dissolved equal amounts of salt in equal amounts of warm water, room-temperature water, and ice water. Which of the following is true?
The salt dissolved most quickly in the warm water.
The salt dissolved most quickly in the room-temperature water.
The salt dissolved most quickly in the ice water.
none of the above
31. A solution that contains more solute than it would normally hold at that temperature is said to be
saturated.
unsaturated.
supersaturated.
concentrated.
32. Which of the following is NOT a property of an acid?
tastes sour
usually reacts with a metal
changes the color of an indicator
feels slippery
33. A base is defined as a compound that produces
hydroxide ions in solution.
hydrogen ions in solution.
hydronium ions in solution.
sodium ions in solution.
34. A small amount of acid is added to a buffer solution. The pH of the solution will34. stay about the same.
35. Uranium-238 undergoes alpha decay. Therefore, uranium-238 will
remain stable.
36. What type of radiation is emitted when polonium-212 forms lead-208?
an alpha particle
a beta particle
gamma radiation
all of the above
37. Transmutation involves
nuclear change.
chemical change.
both a nuclear change and a chemical change.
neither a nuclear nor a chemical change.
38. During nuclear fission, great amounts of energy are produced from
very small amounts of mass.
tremendous amounts of mass.
a series of chemical reactions.
particle accelerators.
39. Which of the following conversion factors would you use to change 18 kilometers to meters?
1000 m/1 km
1 km/1000 m
100 m/1 km
1 km/100 m
40. According to John Dalton’s observations, when elements combine in a compound,40. the ratio of their masses is always the same.
41. Which of the following provides the best analogy for an electron in an atomic orbital?
a cow grazing in a pasture
a bird resting on a tree branch
an ant crawling on the surface of a leaf
a bee hovering around a bee hive
42. The tendency of an element to react is closely related to
its atomic mass.
attractions between its atoms.
the number of valence electrons in atoms of the element.
the ratio of protons to neutrons in atoms of the element.
21. Most metals are brittle
22. Increases from top to bottom within the group.
23. Neon is the most stable element because its highest occupied energy level is filled.
24. transfer of electrons.
25. electrons are not shared equally between atoms
26. BeCl2
27. double-replacement and decomposition
28. exothermic
29. The reaction rate decreases.
30. The salt dissolved most quickly in the warm water
31. Saturated
32. feels slippery
33. hydroxide ions in solution.
34. stay about the same.
35-40: I do not know.
41. a bee hovering around a bee hive
42. the number of valence electrons in atoms of the element.