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The determination of the sources of copper ore used in the m
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27 Jun 2018, 12:37
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The determination of the sources of copper ore used in the manufacture of copper and bronze artifacts of Bronze Age civilizations would add greatly to our knowledge of cultural contacts and trade in that era. Researchers have analyzed artifacts and ores for their concentrations of elements, but for a variety of reasons. these studies have generally failed to provide evidence of the sources of the copper used in the objects. Elemental composition can vary within the same copper-ore lode, usually because of varying admixtures of other elements, especially iron, lead, zinc, and arsenic. And high concentrations of cobalt or zinc, noticed in some artifacts, appear in a variety of copper-ore sources. Moreover, the processing of ores introduced poorly controlled changes in the concentrations of minor and trace elements in the resulting metal. Some elements evaporate during smelting and roasting: different temperatures and processes produce different degrees of loss. Finally, flux, which is sometimes added during smelting to remove waste material from the ore, could add quantities of elements to the final product.
An elemental property that is unchanged through these chemical processes is the isotopic composition of each metallic element in the ore. Isotopic composition. the percentages of the different isotopes of an element in a given sample of the element, is therefore particularly suitable as an indicator of the sources of the ore. Of course, for this purpose, it is necessary to find an element whose isotopic composition is more or less constant throughout a given ore body but varies from one copper ore body to another or, at least, from one geographic region to another.
The ideal choice, when the isotopic composition is used to investigate the source of copper ore, would seem to be copper itself. It has been shown that small but measurable variations occur naturally in the isotopic composition of copper. However, the variations are large enough only in rare ores; between samples of the common ore minerals of copper, isotopic variations greater than the measurement error have not been found. An alternative choice is lead, which occurs in most copper and bronze artifacts of the Bronze Age in amounts consistent with the lead being derived from the copper ores and possibly from the fluxes. The isotopic composition of lead often varies from one source of common copper ore to another, with variations exceeding the measurement error; and preliminary studies indicate virtually uniform isotopic composition of the lead from a single copper-ore source. While some of the lead found in an artifact may have been introduced from flux or when other metals were added to the copper ore, lead so added in Bronze Age processing would usually have the same isotopic composition as the lead in the copper ore. Lead isotope studies may thus prove useful for interpreting the archaeological record of the Bronze Age.
Question 1
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Question Stats:
80% (02:38) correct
20% (02:08) wrong based on 30 sessions
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1) The primary purpose of the passage is to
(A) discuss the techniques of analyzing lead isotope composition (B) propose a way to determine the origin of the copper in certain artifacts (C) resolve a dispute concerning the analysis of copper ore (D) describe the deficiencies of a currently used method of chemical analysis of certain metals (E) offer an interpretation of the archaeological record of the Bronze Age
73% (00:52) correct
27% (00:44) wrong based on 33 sessions
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2) The author first mentions the addition of flux during smelting in order to
(A) give a reason for the failure of elemental composition studies to determine ore sources (B) illustrate differences between various Bronze Age civilizations (C) show the need for using high smelting temperatures (D) illustrate the uniformity of lead isotope composition (E) explain the success of copper isotope composition analysis
37% (01:24) correct
63% (01:49) wrong based on 35 sessions
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3) The author suggests which of the following about a Bronze Age artifact containing high concentrations of cobalt or zinc?
(A) It could not be reliably tested for its elemental composition. (B) It could not be reliably tested for its copper isotope composition. (C) It could not be reliably tested for its lead isotope composition. (D) It could have been manufactured from ore from any one of a variety of sources. (E) It could have been produced by the addition of other metals during the processing of the copper ore.
73% (01:34) correct
27% (01:28) wrong based on 26 sessions
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4) According to the passage, possible sources of the lead found in a copper or bronze artifact include which of the following?
I. The copper ore used to manufacture the artifact II. Flux added during processing of the copper ore III. Other metal added during processing of the copper ore
(A) I only (B) II only (C) III only (D) II and III only (E) I, II, and III
77% (00:57) correct
23% (01:24) wrong based on 26 sessions
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5) The author rejects copper as the "ideal choice" mentioned because
(A) the concentration of copper in Bronze Age artifacts varies (B) elements other than copper may be introduced during smelting (C) the isotopic composition of copper changes during smelting (D) among common copper ores, differences in copper isotope composition are too small (E) within a single source of copper ore, copper isotope composition can vary substantially
93% (01:06) correct
7% (00:47) wrong based on 27 sessions
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6) The author makes which of the following statements about lead isotope composition?
(A) It often varies from one copper-ore source to another. (B) It sometimes varies over short distances in a single copper-ore source. (C) It can vary during the testing of artifacts, producing a measurement error. (D) It frequently changes during smelting and roasting. (E) It may change when artifacts are buried for thousands of years.
57% (01:30) correct
43% (01:40) wrong based on 28 sessions
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7) It can be inferred from the passage that the use of flux in processing copper ore can alter the lead isotope composition of the resulting metal EXCEPT when
(A) there is a smaller concentration of lead in the flux than in the copper ore (B) the concentration of lead in the flux is equivalent to that of the lead in the ore (C) some of the lead in the flux evaporates during processing (D) any lead in the flux has the same isotopic composition as the lead in the ore (E) other metals are added during processing
Re: The determination of the sources of copper ore used in the m
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04 Dec 2018, 02:20
1
Expert Reply
Dear Sir,
The tag has just the purpose to pinpoint the source. Keep in mind that some questions come from the og 10th edition and are present in the powerprep software. In that case will be there a double tag.
Re: The determination of the sources of copper ore used in the m
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21 Aug 2019, 11:10
3
1. The very first sentence proves this, “The determination of the sources of copper ore used in the manufacture of copper and bronze artifacts of Bronze Age civilizations would add greatly to our knowledge of cultural contacts and trade in that era.” Hence, B.
2. If you refer to the first place where the addition of flux is mentioned, author illustrated the failure of this study. “Finally, flux, which is sometimes added during smelting to remove waste material from the ore, could add quantities of elements to the final product.”
3. From this part, we can choose D. “And high concentrations of cobalt or zinc, noticed in some artifacts, appear in a variety of copper-ore sources.”
4. “While some of the lead found in an artifact may have been introduced from flux or when other metals were added to the copper ore, lead so added in Bronze Age processing would usually have the same isotopic composition as the lead in the copper ore.” So, all 3.
5. “The ideal choice, when the isotopic composition is used to investigate the source of copper ore, would seem to be copper itself. It has been shown that small but measurable variations occur naturally in the isotopic composition of copper. “As per this part, option D is correct.
6. As per this part of the passage, “The isotopic composition of lead often varies from one source of common copper ore to another”.
7. “ The isotopic composition of lead often varies from one source of common copper ore to another” Due to this point, option D is correct answer.
Re: The determination of the sources of copper ore used in the m
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27 Jul 2020, 03:06
in regard to Q27, it's worth noting that the author has provided a leeway to the possibility of the lead in flux causing the change in the isotopic concentration of the lead in the ore .To quote from the passage, "While some of the lead found in an artifact may have been introduced from flux or when other metals were added to the copper ore, lead so added in Bronze Age processing would usually have the same isotopic composition as the lead in the copper ore. " The important word is "usually", that can be interpreted as "not surely 100% of the times." Every option mentions lead added in flux(the external additive) which usually(not surely every time) has the same isotopic composition, but option D has mentioned it explicitly and clearly(D. "any lead in the flux has the same isotopic composition as the lead in the ore"). Thus, D.
Re: The determination of the sources of copper ore used in the m
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05 Oct 2020, 08:48
2
I got question number 3 incorrect This is location specific question "And high concentrations of cobalt or zinc, noticed in some artifacts, appear in a variety of copper-ore sources." But it is easy to be driven by the preceding sentence " , usually because of varying admixtures of other elements, especially iron, lead, zinc, and arsenic." Because of this I marched towards the trap E. But we don't know whether cobalt or zinc was produced because of the addition of admixtures. It is just that Cobalt and Zinc are found in different copper ores and mere presence of Cobalt and zinc cannot hint us towards any particular type of ore because it is found in many ores! ANSWER: D
I guess question number 4 is also little tricky if we rely only in last paragraph which has mentioned only flux and copper ore. It is in 1st paragraph "...because of varying admixtures of other elements,especially iron, lead, zinc, and arsenic." that hints towards III as well.
Re: The determination of the sources of copper ore used in the m
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08 Apr 2022, 02:56
Expert Reply
Wowww. I have to admit. Very rarely, I have a hard time figuring out a question. But THIS was crazy. I spent 3 fully minutes pinpointing some decent anchor points to bring me to the solution
First of all, we do have this
Quote:
Moreover, the processing of ores introduced poorly controlled changes in the concentrations of minor and trace elements in the resulting metal. Some elements evaporate during smelting and roasting: different temperatures and processes produce different degrees of loss. Finally, flux, which is sometimes added during smelting to remove waste material from the ore, could add quantities of elements to the final product.
We can infer that every single process creates a variation in the elements of the ore. However, controlled. The variations a tiny up or less the average line
Then we have this very far from the portion above. Almost in the end
Quote:
and preliminary studies indicate virtually uniform isotopic composition of the lead from a single copper-ore source. While some of the lead found in an artifact may have been introduced from flux or when other metals were added to the copper ore, lead so added in Bronze Age processing would usually have the same isotopic composition as the lead in the copper ore.
So from the first part we do have during the process of the ore ALWAYS some variation of the elements UNLESS the lead is present or inducted by the flux
ore isotopic composition = lead isotopic composition
Re: The determination of the sources of copper ore used in the m
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26 Jul 2022, 02:50
Quote:
1) The primary purpose of the passage is to
(A) discuss the techniques of analyzing lead isotope composition (B) propose a way to determine the origin of the copper in certain artifacts (C) resolve a dispute concerning the analysis of copper ore (D) describe the deficiencies of a currently used method of chemical analysis of certain metals (E) offer an interpretation of the archaeological record of the Bronze Age
For long passages, especially like this one, how to tackle especially this question?
Re: The determination of the sources of copper ore used in the m
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26 Jul 2022, 03:06
1
Expert Reply
SivhHarish wrote:
Quote:
1) The primary purpose of the passage is to
(A) discuss the techniques of analyzing lead isotope composition (B) propose a way to determine the origin of the copper in certain artifacts (C) resolve a dispute concerning the analysis of copper ore (D) describe the deficiencies of a currently used method of chemical analysis of certain metals (E) offer an interpretation of the archaeological record of the Bronze Age
For long passages, especially like this one, how to tackle especially this question?
I am sorry, truly. I apologize with the entire community for not doing yet the new RC guide Forgive me
This is the way to have the main idea
Attachment:
GRE RC thinking Spectrum .jpg [ 201.08 KiB | Viewed 3242 times ]
The main idea is NOt something you find witt logic but rather is a common sense. It is a feeling you have reading the passage.
Basically is this
1) read the passage 2) get sense of it fully 3) going through POE of the answer choices 4) Having the big picture in mind: not too broad and not too narrow
Re: The determination of the sources of copper ore used in the m
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10 Sep 2023, 14:48
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