atomic phenomena

[hotstepper]

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How important is it to memorize the following formulas:

wien's displacement law: lambda(peak) x T=constant
stefan-boltzmann law: E(total)=sigma x T^4

for bohr's model...
angular momentum=rh/2n
energy of electron: E=-RH/n^2
electromagnetic energy of photons=E=hc/lambda

and for the photoelectric effect...
E=hf=hc/lambda
K=hf-W

Also, how important is it to understand blackbody radiation? Can someone please give a simple description?

It seems like Kaplan focuses a lot on the above formulas/concepts but EK simply ignores them. So, should I spend time memorizing and understanding them?

 

[MT Headed]

E=hf

I would keep this one. Most of the others I've never even heard of. For the other formulas, if it's needed I'm sure the MCAT will give it to you.

For black body radiation, there is a formula you should probably look up, but the important concept is that everything radiates. You radiate energy to the world. The world radiates energy back to you. Go look up the formula to see what kinds of factors affect the amount of radiation you emit to the world, and the world emits to you. Hint: it's really really sensitive to the temperature of the thing doing the radiating.

 

[whiteshadodw]

Go to the AAMC website. download the topics list. they have all the formulas you need to memorize. anything that isn't on there, will probably be given to you. however, conceptually, i would know everything on that last and know how it can be effected.

 

[MT Headed]

Go to the AAMC website. download the topics list. they have all the formulas you need to memorize. anything that isn't on there, will probably be given to you. however, conceptually, i would know everything on that last and know how it can be effected.

Good one! I forgot they had formulas on there.

lol, even E=hf isn't on the list!

 

[Temperature101]

How important is it to memorize the following formulas:

wien's displacement law: lambda(peak) x T=constant
stefan-boltzmann law: E(total)=sigma x T^4

for bohr's model...
angular momentum=rh/2n
energy of electron: E=-RH/n^2
electromagnetic energy of photons=E=hc/lambda

and for the photoelectric effect...
E=hf=hc/lambda
K=hf-W

Also, how important is it to understand blackbody radiation? Can someone please give a simple description?

It seems like Kaplan focuses a lot on the above formulas/concepts but EK simply ignores them. So, should I spend time memorizing and understanding them?

K= hf-W...I think was on AAMC3, but it was given on the passage.

 

[MD Odyssey]

Good one! I forgot they had formulas on there.

lol, even E=hf isn't on the list!

That's surprising. I would know that the energy of a photon is proportional to its frequency and that the constant of proportionality is Planck's constant. I would also make sure you could readily convert that to an expression involving wavelength. Other than that, the other equations are not something that the MCAT will expect you to know - if it appears on the MCAT, I would imagine it would be explained in a passage.

I would understand the mechanics of the photoelectric effect and understand the concept of the work function - memorizing an equation for this is irrelevant. Also, blackbody radiation is probably something which, if it were to appear on the exam, would be described in a passage.

I had a friend that took the Kaplan course and he mentioned to me that the course placed a heavy emphasis upon the Bohr model of the atom. I have no idea if that degree of emphasis is accurate or not.

 

[whiteshadodw]

i don't want to give away certain things or not. but i just took a few practice tests and it showed up. the only reason i knew what was going on was because i had taken pchem. but for all intents and purposes, E = hf was given. however, there was another physics question requiring you to recall a formula which is not in the topics list, and yet another question recalling a formula that isn't in the topics list. of course, i remembered one off the top of my head, but couldn't remember the other.

also, regarding the photoelectric effect and work function. this is closely related to ionization energies. for example, it will take a photon of higher energy to ionize Mg than Na since the first ionization energy of Mg is higher than Na.

also, as an aside, there are bound to be things on the AAMC topics list that we might not have seen in our prereqs. but that doesn't mean they aren't fair game. if i was learning some of those things for the first time i would definitely read a textbook, go to khan academy, or academic earth, or w/e. prime example of something that receives some significant attention in the AAMC topics list, but very weakly covered in TBR = nuclear physics. i would highly suggest reading a textbook if you never learned this stuff because it never made sense in TBR.