PrepTest 158, Section 3, Question 10
Radioactive elements may have been created when the(70 more words not shown)
Which one of the following(9 more words not shown)
- AAny radioactive elements(12 more words not shown)
- BRadioactive elements are(6 more words not shown)
- CIf no new(20 more words not shown)
- DIt is possible(9 more words not shown)
- EDue to their(19 more words not shown)
Reading the argument
If these elements keep decaying, why are so many still here?
That's the reasoning behind the author's claim that radioactive elements are still being created. Most decay into nonradioactive elements within a few million years. If the supply came only from the beginning of the universe and nothing replenished it, the argument says almost none would remain. Yet there are plenty today. The author takes that abundance as evidence of continued creation.
Notice the difference between the first two claims. Radioactive elements may have existed at the beginning; that is presented as a possibility. Their continued creation today is what the author confidently argues for. Everything about decay and the supply remaining today is offered to support that second claim.
What we’re looking for
For the main conclusion, I want “Radioactive elements are still being created.” Don't pick one of the steps explaining why the author believes it.
Working the answers
- A
The decay of the original elements is part of the explanation for needing a new supply. It isn't the point the argument is trying to establish. Also, the passage says most elements decay within the stated period; it doesn't separately establish the fate of every original element. Our answer should capture the stated claim about continued creation.
- BCorrect
Radioactive elements are being created today. The author states that claim near the beginning and then explains why the present abundance would be hard to account for if no new elements were being created. B gives the claim supported by the rest of that reasoning.
- C
This is a supporting step: without later creation, almost none would be left. The author combines it with the observation that many are left to argue for continued creation. A sentence can contain important reasoning and still serve as support for a larger point.
- D
This is the tentative background claim. The author allows that radioactive elements may have existed when the universe began, then says that even if they did, new ones are still being created. D leaves out the point the argument goes on to defend.
- E
Instability and decay explain why an original supply wouldn't last in abundance. That fact helps support the claim about new creation, but the author isn't primarily trying to convince us that radioactive elements decay. The argument uses that information to explain why more must be being made.
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