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Check My Chemistry Math Please


Can someone familiar with frequency, energy and momentum of a photon check this work for me please? I'm actually stuck on how to manipulate the information I have to solve the momentum equation p=mv. That's the correct one right?


First question was to find the frequency of the radiation if a photon has a wavelength of 5320 Angstroms. My work was...

V=speed of light/wavelength

1)(3.00x10^8 m/s/5320 Angstroms) *(10^-10)=5.64x10^-5 s-1

Did I do that right? I believe I had to multiply the answer by (10^-10) because that's how many angstroms are in a meter which would allow those units to cancel.

Then I need to find energy.

2) E=hv


I'm not sure of the exponents in the final answer as I don't have a scientific calculator on hand and the web ones won't give me an answer other than zero for that math. I'm assuming it's like -28 or so?

Ok so given that the above information is correct how would I use that to find the momentum of the photon?

Any help is greatly appreciated, thank you!


let us put in your pooper first, ho. you know how we do.


ahhh figured it out, had the wrong momentum equation :slightly_smiling:


I know that F=MA and you can't push on a rope. After that, you're on your own.


You did the first one wrong. Multiply the wavelength by 10E10 first and then divide.

If you think about it logically, if light has a really high velocity, but a tiny ass wavelength, the frequency should be very high to compensate.

Also, stop being a bitch and use 2.9979e8 as the speed of light.


Chemistry, the only area where we can call Way a bitch and get away with it lol


If you still don't have a scientific calculator the answers are:

5,635196579x10^14 Hz
3,73388125x10^-19 Joules

Ninny: Stop being a bitch and use 299792458m/s as c. It's EXACTLY that much.

If you need me I'll be in the "Enter your bid for a T-Cell" thread requesting a homework forum.


It's the same thing. Multiplying the denominator by 10^10 is the same thing as multiplying the numerator by 10^(-10), which is what he did.


Also, light is in meters PER SECOND, so small frequency = small denominator = high velocity.


I got 3.73e-38. Think about it, if planks constant is 6.626 x 10^(-34), and the frequency is LESS THAN 1, than your answer has to be smaller than planck's constant (i.e., more decimal places).

All you do is multiply the numbers and add the exponents. So, 6.626e-34 * 5.64e-5 = 37.37e-39 = 3.74e-38

Hope this helps.

Edit: I didn't check your answer in the first one, but the assumptions look right so I'm assuming the 5.64e-5 is correct...and went from there.


Frequency is measured in inverse seconds. The velocity equation is v = wavelength*frequency.

m/s = m*s^-1.

EDIT: COME AT ME BRO. He's probably already turned in his HW lol.

goddamit I got pwnt lol.


What about the other point? Where you told him to multiply the wavelength (in the denominator) by 10e10 first, instead of multiplying the whole thing by 10^-10? How is what he did any different than your suggestion?

Call it a draw?


Crap, dropped the negative lol. Oh well sure, let's have a draw lol.


Leave it to us math majors to get confused by the stupid INVERSE UNIT.

I remember hating chemisty and physics so clearly right now.


Waylander, you need to make friends with nerdy asians, they got me through my college math courses.


Carry the 1.


This is great advice.

If you're looking for coattails to ride to the promised land, make sure they belong to that nerdy Asian kid who comes to lecture with a laptop.


Aren't those usually the guys who play Starcraft II or tetris during lecture?


Ahhh...Chemistry 132. Dr. Hicks.

Brings back memories! : )


They play starcraft II and tetris precisely because they can, whilst taking in every bit of information the lecturer gives them, with incredible accuracy.