Official MCAT Guide - IR radiation

[pm1]

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5. Greenhouse gases absorb infrared radiation in what kind of process?

A. Atomic transitions
B. Molecular vibrational and rotational transitions
C. Molecular dissociation
D. Phase transitions

Answers: B

Can someone PLEASE explain to me why is this the answer? I had no idea how to go about this question.

 

[MedPR]

Heat transfer is accomplished by the events described in answer B. Hot objects = fast moving, cold objects = slow moving. When a bunch of hot objects start bumping into cold objects, they increase the KE of the cold objects. This is a concept you just have to know.

 

[pm1]

Heat transfer is accomplished by the events described in answer B. Hot objects = fast moving, cold objects = slow moving. When a bunch of hot objects start bumping into cold objects, they increase the KE of the cold objects. This is a concept you just have to know.

yay! thanks for answering me MedPR. I was praying that you would look at my thread (people seem to be not as active here anymore 🙁 )

but in regards to the question..
okay I get it about the transfer of heat. but how is that related to infrared radiation and greenhouse gases absorbing it?
sorry if that is a dumb question, I just don't get it. (may be I'm just tired...)

 

[MedPR]

yay! thanks for answering me MedPR. I was praying that you would look at my thread (people seem to be not as active here anymore 🙁 )

but in regards to the question..
okay I get it about the transfer of heat. but how is that related to infrared radiation and greenhouse gases absorbing it?
sorry if that is a dumb question, I just don't get it. (may be I'm just tired...)

Greenhouse gases are known for trapping heat. To trap heat you must absorb heat. If you absorb heat, your molecules gain kinetic energy.

I don't really know how else to explain it :/

 

[pm1]

Greenhouse gases are known for trapping heat. To trap heat you must absorb heat. If you absorb heat, your molecules gain kinetic energy.

I don't really know how else to explain it :/

yep, thats good enough! THANK YOU! 😀

Please keep checking and explaining threads! It is a great help! I really appreciate you trying to answer threads even though you have already taken your test! 👍👍

 

[GeorgiadisMD]

Lol IR only deals with vibration rotation. That question was a giveaway.

Sent from my phone so trie to egnore all erors you gramar nacis