GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 18 Jun 2019, 20:54

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Every element on the periodic chart is radioactive, though

Author Message
TAGS:

### Hide Tags

Intern
Joined: 27 Mar 2012
Posts: 10

### Show Tags

19 Jul 2012, 21:31
1
2
00:00

Difficulty:

(N/A)

Question Stats:

63% (01:18) correct 37% (01:21) wrong based on 154 sessions

### HideShow timer Statistics

Every element on the periodic chart is radioactive, though the most stable elements have half-lives that are thousands and thousands of years long. When an atom decays, it splits into two or more smaller atoms. Even considering the fusion taking place inside of stars, there is only a negligible tendency for smaller atoms to transmute into larger ones. Thus, the ratio of lighter to heavier atoms in the universe is increasing at a measurable rate. Therefore, __________________________.

Which of the following most logically completes the above statements?
1) it is possible to use a shifting ratio of light to heavy atoms to calculate the age of the universe.
2) the fusion taking place inside stars has to produce enough atoms of the heavy elements to offset the radioactive decay of large atoms elsewhere in the universe.
3) without radioactive decay of atoms, there could be no solar combustion and no life as we know it.
4) it is imperative that scientists begin developing ways to reverse the trend and restore the proper balance between the lighter and the heavier elements.
5) there are now more light elements in the universe than heavy ones.
Intern
Joined: 12 Jun 2011
Posts: 2

### Show Tags

19 Jul 2012, 23:21
1 is correct, The last statement indicates that the ratio is increasing and it is measurable. The initial statement gives background on atoms, decay rate & half life indicating various factors for determining age of universe.
Retired Moderator
Status: Flying over the cloud!
Joined: 17 Aug 2011
Posts: 540
Location: Viet Nam
GMAT Date: 06-06-2014
GPA: 3.07

### Show Tags

20 Jul 2012, 09:55
gjg wrote:
Every element on the periodic chart is radioactive, though the most stable elements have half-lives that are thousands and thousands of years long. When an atom decays, it splits into two or more smaller atoms. Even considering the fusion taking place inside of stars, there is only a negligible tendency for smaller atoms to transmute into larger ones. Thus, the ratio of lighter to heavier atoms in the universe is increasing at a measurable rate. Therefore, __________________________.

2) the fusion taking place inside stars has to produce enough atoms of the heavy elements to offset the radioactive decay of large atoms elsewhere in the universe.
3) without radioactive decay of atoms, there could be no solar combustion and no life as we know it.
4) it is imperative that scientists begin developing ways to reverse the trend and restore the proper balance between the lighter and the heavier elements.
5) there are now more light elements in the universe than heavy ones.

I liked this one because It took me quite long time to guest the meaning of the argument. However, my choice is the first one, choice (A). My reasoning is:
(A) it is possible to use a shifting ratio of light to heavy atoms to calculate the age of the universe. => the cause the ratio of lighter to heavier atom in the universe is increasing at a MEASURABLE RATE (this is the keyword for all of this argument) => We can measure the speed of decaying => can calculate the time
(B) HAS TO in this choice is very extreme. And the argument also did not mention the offset between various kind of elements
(C) SOLAR COMBUSTION is irrelevant to the argument
(D) IMPERATIVE is also a extreme word. So, out of scope
(E) This hypothesis that there are now more light elements in the universe than heavy ones is really non-provable because there is no clue in the argument.
_________________
Intern
Joined: 10 May 2012
Posts: 42
GMAT Date: 09-10-2012

### Show Tags

20 Jul 2012, 11:37
Dont understand why cant E be the answer!

what is the OA and OE?
Senior Manager
Joined: 11 May 2011
Posts: 313

### Show Tags

20 Jul 2012, 21:58
1) it is possible to use a shifting ratio of light to heavy atoms to calculate the age of the universe.

Whats OA?
_________________
-----------------------------------------------------------------------------------------
What you do TODAY is important because you're exchanging a day of your life for it!
-----------------------------------------------------------------------------------------
Intern
Joined: 04 Mar 2008
Posts: 37

### Show Tags

21 Jul 2012, 00:06
jaiswalamrita wrote:
Dont understand why cant E be the answer!

what is the OA and OE?

For E to be the conclusion, the proportion of lighter to higher needs to be discussed. which is not the case.
Manager
Joined: 27 May 2010
Posts: 164

### Show Tags

27 Aug 2012, 19:40
Every element on the periodic chart is radioactive, though the most stable elements have half-lives that are thousands and thousands of years long. When an atom decays, it splits into two or more smaller atoms. Even considering the fusion taking place inside of stars, there is only a negligible tendency for smaller atoms to transmute into larger ones. Thus, the ratio of lighter to heavier atoms in the universe is increasing at a measurable rate. Therefore, __________________________.

Which of the following most logically completes the above statements?

2) the fusion taking place inside stars has to produce enough atoms of the heavy elements to offset the radioactive decay of large atoms elsewhere in the universe.

Went with 2. Can someone give an explanation. I though the negligible tendency for smaller atoms to transmute into larger ones paralleled 2.
Intern
Joined: 12 Feb 2012
Posts: 25
Location: United States
GMAT Date: 08-30-2012

### Show Tags

28 Aug 2012, 00:50
Except B & E , other options are just far away from the ans.
I was eliminated E because it says " there are now more light elements in the universe than heavy ones." .It might be true , But we dont know the current conditions ...so it seems difficult to conclude .....
So ,I would go with B
BTW what is the OA ????
_________________
KUMAR GAURAB
Intern
Joined: 21 Aug 2012
Posts: 16

### Show Tags

28 Aug 2012, 03:03
grbjha wrote:
Except B & E , other options are just far away from the ans.
I was eliminated E because it says " there are now more light elements in the universe than heavy ones." .It might be true , But we dont know the current conditions ...so it seems difficult to conclude .....
So ,I would go with B
BTW what is the OA ????

Per me the answer is A. Ruling B out as there is no mention in the passage about requirement to offset the increase in ratio of lighter atoms. On the otherhand Passage does mention that Shift towards lighter atoms is mesureable hence A makes a better choice.
_________________
Senior Manager
Joined: 24 Mar 2010
Posts: 337

### Show Tags

28 Aug 2012, 21:09

B makes a normative statement that is not supported by the stimulus. Nowhere does it say that fusion within stars NEEDS to offset radioactive decay elsewhere.

E is NOT the answer because the question stimulus says that the RATIO of light to heavy atoms is increasing at a measurable rate. However, that tells us nothing about the ABSOLUTE number of light atoms in the universe vs. heavy. For instance, let's say that a million years ago there was 1 billion light atoms and 10 billion heavy atoms, for a ratio of 1:10. Now, there is 5 billion light atoms and 6 billion heavy atoms, for a ratio of 5:6. The ratio has certainly increased a lot, but there is still more heavy atoms. So we cannot conclude based on the information given that E holds true. This is the classic ratio vs raw number trick that the GMAT loves to pull.

A is correct because it makes the correct conclusion based on the information given. If the ratio of light to heavy atoms is increasing at MEASURABLE (key word for this question) rate, then we can mathematically figure out the age of the universe since this fusion process has been going on since the beginning of the universe.
Intern
Joined: 06 Jul 2012
Posts: 30

### Show Tags

28 Aug 2012, 23:57
I'l go with A.

The choice gives relation between 2 premises - half lives and ratios of lighter to heavier atoms.
Knowing these 2 and we can calculate the speed with which the division of an heavier atom to lighter atom is going on, and thus the life of universe when compared with the actual life of undivided atom, can be calculated.

regards
_________________
If you think you are lost, you are.
Intern
Joined: 07 Feb 2008
Posts: 48
Location: United States
WE: Consulting (Computer Software)

### Show Tags

29 Aug 2012, 02:32

keywords are "increasing at a measurable rate"

so, increasing rate = shifting ratio can be used to determine the age of the universe
Intern
Joined: 16 Jul 2012
Posts: 13
Location: United States
GMAT 1: 710 Q49 V38
GPA: 3.5

### Show Tags

29 Aug 2012, 09:20
OA is A

Manager
Status: exam is close ... dont know if i ll hit that number
Joined: 06 Jun 2011
Posts: 136
Location: India
GMAT Date: 10-09-2012
GPA: 3.2

### Show Tags

29 Aug 2012, 11:15
good question ..
i missed it
but now i understand how it works ..whenever we digress from the conclusion the chances of missing the question are very high
_________________
just one more month for exam...
Board of Directors
Joined: 01 Sep 2010
Posts: 3363

### Show Tags

29 Aug 2012, 12:12
mohan514 wrote:
good question ..
i missed it
but now i understand how it works ..whenever we digress from the conclusion the chances of missing the question are very high

Even though I do not like LSAT question because they do not resemble real GMAT questions, I like this one.

In complete the argument whenever you see SINCE or BECAUSE at the end of the stimulus is a strenghtening or assumption question, but in other cases you have to weakening or find the paradox or conclusion.......in sum, you have to rely on the context of the same and then evaluate your response accordingly.

2) the fusion taking place inside stars has to produce enough atoms of the heavy elements to offset the radioactive decay of large atoms elsewhere in the universe. here is not the point

3) without radioactive decay of atoms, there could be no solar combustion and no life as we know it. once againg, here is not the point at end

4) it is imperative that scientists begin developing ways to reverse the trend and restore the proper balance between the lighter and the heavier elements. too extreme and also wrong because we are not concerned to reverse any trend

5) there are now more light elements in the universe than heavy ones. we can't infer this because we are talking about of ratio

1) it is possible to use a shifting ratio of light to heavy atoms to calculate the age of the universe. looking at the stimulus we have "Every element on the periodic chart is radioactive, though the most stable elements have half-lives that are thousands and thousands of years long" and "the ratio of lighter to heavier atoms in the universe is increasing at a measurable rate."......so a shifting

_________________
Non-Human User
Joined: 01 Oct 2013
Posts: 4610

### Show Tags

09 Jan 2019, 19:55
Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: Every element on the periodic chart is radioactive, though   [#permalink] 09 Jan 2019, 19:55
Display posts from previous: Sort by