#15 - Physicists attempting to create new kinds of atoms

[Administrator]

Please post your questions below! Thank you!

[DJYoungCorduroy]

I chose C. I think it is wrong because this answer choice does not necessarily describe a phenomenon that triggers the sufficient condition in that there could be collisions that take place with just enough energy or some medium amount of energy, and heat is not produced. (We only know that heat is actually produced IF the amount of energy "greatly exceeds the minimum required").

In other words, the sufficient condition wasn't met, so we can't say anything about the necessary condition (or in logic game terms, "the rule falls away").

Also, I was about to say that I don't think E must be true, but then read the stem again, and it says most strongly supported...not must be true. So I'm much more comfortable with E now that I realize it's "supported" and not "MBT."

Am I right in my thinking as to why C is wrong?

[James Finch]

Hi Young Cord,

The issue with answer choice (C) is that the stimulus is stating that the differential between the energy needed to overcome the force of repulsion between the two atoms and the actual energy at which they collide is what generates heat (the heat being the differential). So even if it takes much more energy for two larger atoms to fuse than two smaller ones, if the speed at which they're moving is exactly the right amount to overcome the force of repulsion, no heat heat will be created when they fuse. Similarly, if two smaller atoms are fused together, even at far smaller energy levels, but those levels are double or triple the energy needed to overcome the repulsion, that excess energy will become heat. The absolute energy isn't relevant to production of heat, only the differential between what is needed and what is actually present at fusion.

The second issues is what happens after fusion: if there is no heat, it seems that the resulting atom is relatively stable. But we are told that if there is a lot of heat generated by excess energy, then the atom is likely to split again. Put all these element together, as a Must Be True question demands, and we get an answer similar to (E):

Large energy differential Heat Likely to split

Large energy differential Likely to split

Regarding the language, the LSAT always hedges whenever something isn't 100% true. Here we get words like "likely" and "most strongly supported" to show that this is a probabilistic outcome, not a predetermined one. Still, the process for answering a MBT is the same whether it will 100% always be true or is only a likely outcome: synthesizing the premises into a solid Prephrase, and seeing which answer choice falls in line with that prephrase.

Hope this helps!

[DJYoungCorduroy]

Dankeshoen

[bukkaabh]

Hi, I'm having some trouble understanding why D is wrong and E is right. The last sentence of the stimulus says that "[The] hotter the atom is, the greater the chance that it will immediately split apart again." In Answer Choice, E, it says that the new atom will be likely to split apart again - I thought that just because something has a greater chance of doing something, doesn't mean it is likely to happen, and thus I eliminated E as a contender.

I thought that D went along more closely with the stimulus, even though it also is not perfect because there could be a gray area where energy is produced by the collision and it still does not split apart.

Can someone please explain why E is the correct choice even though the "greater the chance" and "likely" don't really match up?

[Dave Killoran]

Hi B,

Thanks for the question! The key point in considering LSAT answers that you know are correct is to try to determine why the test makers think they are correct. That will do far more towards improving your score than focusing on perceived problems (which you know by definition that the test makers do not think were problematic enough). And, do the reverse to wrong answers: focus on why LSAC says they are wrong. Your job then, in a nutshell, is to try to figure out what the heck LSAC is thinking. The better you can do that, the higher your score will go

In this case, note how answer choice (E) sets up: "If two atoms collide with considerably more energy..." that "considerably more" part is key towards sustaining the point made later in (E) that the new atom will re-split. Is it perfect? No, but it doesn't have to be since this is an MSS stem, and the way they phrased (E) certainly allows this to be the most supported answer of the five.

Thanks!

[sammydz]

I understood the stimulus very well. There's an electric field repelling two atoms. In inorder to fuse them, there must be a force just a bit more than the magnetic field. But if too much force is used, excess energy is created. the more excess energy is created, the greater the chance it will split again.
This is what I understand. If a negligible amount of excess energy is created, there's A CHANCE it immediately splits again. The greater the excess heat created, THE GREATER THE CHANCE.
Since the use of language is very particular when it comes to the LSAT, "answer choice E" is not supported at all.
The hottest atom created using the most considerable amount of excess energy may only have a 49% chance of immediately splitting again.
the language "likely" used in answer choice "E" implies a chance greater than 50%.


ps. I appreciated the June crystal ball seminar; this specific LR was recommended for study. please help me explain this particular example.