Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 0410:00 AM PDT
-11:00 AM PDT
What does test anxiety really look like on the GMAT? For many test takers, it does not look like a panic attack. Instead, it shows up as brain fog, rereading, negative comparisons, mental noise....
Sep 0201:00 PM EDT
-11:59 PM EDT
Take 30% off all study plans with code COURSEWORK - Expires on Monday 9/7
Sep 0401:30 AM EDT
-02:30 AM EDT
This Labor Day, turn your hard work into real score gains. From 615→715 in 15 days to 705 in 30 days, our students prove what's possible with personalized, expert guidance. Save up to 25% on 1-on-1 tutoring.
Sep 0609:30 AM EDT
-12:30 PM EST
Top scores are possible when you enroll in a powerful EA course, taught live online + 6 months access to TTP OnDemand video courses included! Perfect class schedule and easy course access for working professionals. Class starts Sundays Sept. 6, 2026.- Sep 07
12:01 AM PDT
-11:59 PM PDT
On the 7th, GMAT Club Tests will be Free! Including all the Quizzes, Questions, and Tests. 12 AM - 11:59 PM PDT 
Sep 0712:30 AM EDT
-01:30 AM EDT
Tejas studied hard but kept repeating the same mistakes. After 3 attempts at 645, a focused 4-week strategy helped him identify and fix what was holding him back—leading to a 695 with just 12–15 hours of study per week.- Sep 07
10:00 AM PDT
-11:00 AM PDT
A complete walkthrough of GMAT Club’s free 12-week GMAT study plan: what you study each week, how progress and goals are tracked, how the error log works, and how your practice unlocks paid tools at no cost. - Sep 09
07:00 AM PDT
-10:00 AM PDT
Meet AdComs and explore top Master’s programs - MiM, MiF, MSc, MSBA and more. - Application Fee Waivers - Free 1-Week of GMAT Club Tests: - Master's Application Toolkit - Grand Prize Giveaway - Sep 09
10:00 AM PDT
-11:00 AM PDT
Three MBA applications. Three rejections. No interview invites. A year later, Aman was admitted to Cambridge Judge, SMU, and IMD. In this episode of MBA Admit Stories, Aman shares how he rebuilt his MBA application... 
Sep 1008:00 PM PDT
-09:00 PM PDT
Free- full-length test + 15 concept videos + 150+ short videos + study plan!
Sep 1507:00 PM EDT
-09:00 PM EST
Elite scores are possible when you enroll in a powerful GMAT course, taught live online + 6 months access to TTP OnDemand video courses included! Class starts Tues/Thurs Sept. 15, 2026 - Nov. 15, 2027, 7:00pm-9:00pm EST
Sep 2108:00 PM EDT
-10:00 PM EDT
Boost your GMAT score in less than one month in a live online class + 6 months access to TTP OnDemand video courses included! Class starts Mon, Tues, Wed, Thur, Fri Sept. 21, 2026 - Oct. 9, 2027, 7:00pm-10:00pm EST
16 Apr 2011, 21:14
Kudos
Bookmarks
While popular science tends to favor extragalactic astronomical research that emphasizes current challenges to physics, such ass the existence of dark matter, dark energy, and Cosmic inflation, significant research continues to take place in the field of planetary astronomy on the formation of our own solar system. In early attempts to explain this phenomenon, astronomers believed in the encounter, or"rogue star", hypothesis, which suggests that matter was tidally stripped away from our sun as a larger star passed within a gravitationally-significant distance some billions of years ago. The encounter hypothesis postulates that after being stripped away, the matter cooled as it spun father from the sun, and formed planets with their own centers of gravity. This hypothesis conveniently accounts for the fact that all planets in the solar system revolve in the same direction around the sun; it is also consistent with the denser planets remaining closer to the sun, and the more gaseous planets traveling further away.
The encounter hypothesis explained the phenomenon sufficiently enough that it allowed scientists to focus on more immediately rewarding topics in physics and astronomy for most of the first half of the 20th century. Closer investigation, however, found several significant problems with the encounter hypothesis, most notably that the hot gas pulled from the sun would not condense to form dense planets, but rather would expand in the absence of a central, gravitational force. Furthermore, the statistical unlikelihood of a star passing in the (astronomically speaking) short time of the sun's existence required scientists to abandon the encounter hypothesis in search of a new explanation. Soon after astronomers formed a second theory, the nebular hypothesis, which submits that the solar system began as large cloud of gas containing the matter that would form the sun and its orbiting planets. The nebular hypothesis suggests that angular momentum would have morphed the nebular into a protoplanetary disc, with a dense center that generated intense heat and pressure, and a cooler, thinner mass that revolved around it. The central mass would have continued to build in density and heat, forming the sun, while the centrifugal force around the disc's edge kept smaller masses from being pulled in to the sun; those masses, upon cooling, would break off to become planets held in orbit by the competing gravitational force of the sun and centrifugal force of their orbital inertia.
The nebular hypothesis, however well it explained the sun's formation, remained problematic in its ability to account for the formation of several planets with differing physical and chemical properties. Encouraged by their advance toward a provable hypothesis for the solar system, scientists have recently come to adopt a third hypothesis, the protoplanet hypothesis. This currently accepted theory holds that the gaseous cloud that would form the solar system was composed of particles so cold that even the heat of the forming sun could not significantly impact the temperature of the outer reaches of the cloud. Gas in the inner region, within what scientists refer to as the frost line, was quickly either burned or dispersed, leaving a small amount of metallic matter, such as nickel and iron, to form the inner planets. Such matter would need to have an extremely high melting point to avoid becoming liquefied, ensuring that Mercury, Venus, Earth, and Mars would remain small and dense. Outside the frost line, however, gas was kept cool enough to remain in solid, icy states. Over time, planets such as Jupiter and Saturn would amass large quantities of frozen gas, enough to grow to hundreds of times the size of the Earth.
1. Which of the following discoveries, if true, would best support the protoplanet hypothesis that the temperature difference is responsible for the different sizes of planets on either side of the frost line?
A. The core of Saturn and the core of Mercury are found to be 98% composed of the same materials.
B. The cores of Saturn and Jupiter are found to each contain at least five chemical elements not found in the other.
C. The core of the Earth and the core of Mars are found to be comprised of the same mix of chemical elements.
D. A nearby star is found to be orbited by six planets, and the size of each is inversely proportional to its distance form the star.
E. The Earth;s moon is found to have a vastly different composition from that of the moons of Jupiter.
The encounter hypothesis explained the phenomenon sufficiently enough that it allowed scientists to focus on more immediately rewarding topics in physics and astronomy for most of the first half of the 20th century. Closer investigation, however, found several significant problems with the encounter hypothesis, most notably that the hot gas pulled from the sun would not condense to form dense planets, but rather would expand in the absence of a central, gravitational force. Furthermore, the statistical unlikelihood of a star passing in the (astronomically speaking) short time of the sun's existence required scientists to abandon the encounter hypothesis in search of a new explanation. Soon after astronomers formed a second theory, the nebular hypothesis, which submits that the solar system began as large cloud of gas containing the matter that would form the sun and its orbiting planets. The nebular hypothesis suggests that angular momentum would have morphed the nebular into a protoplanetary disc, with a dense center that generated intense heat and pressure, and a cooler, thinner mass that revolved around it. The central mass would have continued to build in density and heat, forming the sun, while the centrifugal force around the disc's edge kept smaller masses from being pulled in to the sun; those masses, upon cooling, would break off to become planets held in orbit by the competing gravitational force of the sun and centrifugal force of their orbital inertia.
The nebular hypothesis, however well it explained the sun's formation, remained problematic in its ability to account for the formation of several planets with differing physical and chemical properties. Encouraged by their advance toward a provable hypothesis for the solar system, scientists have recently come to adopt a third hypothesis, the protoplanet hypothesis. This currently accepted theory holds that the gaseous cloud that would form the solar system was composed of particles so cold that even the heat of the forming sun could not significantly impact the temperature of the outer reaches of the cloud. Gas in the inner region, within what scientists refer to as the frost line, was quickly either burned or dispersed, leaving a small amount of metallic matter, such as nickel and iron, to form the inner planets. Such matter would need to have an extremely high melting point to avoid becoming liquefied, ensuring that Mercury, Venus, Earth, and Mars would remain small and dense. Outside the frost line, however, gas was kept cool enough to remain in solid, icy states. Over time, planets such as Jupiter and Saturn would amass large quantities of frozen gas, enough to grow to hundreds of times the size of the Earth.
1. Which of the following discoveries, if true, would best support the protoplanet hypothesis that the temperature difference is responsible for the different sizes of planets on either side of the frost line?
A. The core of Saturn and the core of Mercury are found to be 98% composed of the same materials.
B. The cores of Saturn and Jupiter are found to each contain at least five chemical elements not found in the other.
C. The core of the Earth and the core of Mars are found to be comprised of the same mix of chemical elements.
D. A nearby star is found to be orbited by six planets, and the size of each is inversely proportional to its distance form the star.
E. The Earth;s moon is found to have a vastly different composition from that of the moons of Jupiter.
OA is C
I first chose D, since I couldn't find any information about the component about the core of the Earth and the core of Mars are the same chemical elements from the passage. Please indicate. thanks!
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Reading Comprehension (RC) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
17 Apr 2011, 00:54
Kudos
Bookmarks
D suggests the "encounter hyp" - since the planets away from the centre will be less dense
This hypothesis conveniently accounts for the fact that all planets in the solar system revolve in the same direction around the sun; it is also consistent with the denser planets remaining closer to the sun, and the more gaseous planets traveling further away.
However C is a defender assumption since it precludes an alternate explanation for the difference in the size of the plants except for the frost line theory. i.e. the matter within the frost line is denser however the matter outside the frost line is thin and cold. That explains why the planets could have increased the size by amassing more frozen gas on the outside.
This hypothesis conveniently accounts for the fact that all planets in the solar system revolve in the same direction around the sun; it is also consistent with the denser planets remaining closer to the sun, and the more gaseous planets traveling further away.
However C is a defender assumption since it precludes an alternate explanation for the difference in the size of the plants except for the frost line theory. i.e. the matter within the frost line is denser however the matter outside the frost line is thin and cold. That explains why the planets could have increased the size by amassing more frozen gas on the outside.
17 Apr 2011, 14:54
Kudos
Bookmarks
gmat1220
Sorry, but I'm still confusing about "the same mix of chemical elements" from the answer C. For this question, I should look for information in the last paragraph,
Quote:
...From what I understood, this part mentions the relation between temperature and the planets, but it doesn't really mention the relation between temperature and the different sizes of planets.
So how can I answer this question by getting the correct information from the passage?
Thanks,
