ok whos a chemistry nut???

[Dend78]

im lost and needing some guidence here

from what ive read this stuff is supposed to be basic stuff but i dont quite understand where the stuff is coming from

here are the instructions

"Uranium-238 decays through a serise of emissions of Alpha or Beta particles until it becomes lead-206. In the char below, fill in the missing particles and lablel the type of emission or each step.

1.) Uranium-238 ---> Thorium-234 + _____

now if im understanding since the uranium is heavy it looses 4 alpha particles, so the number 4 is atomic weight for helium so to balance this out its

238U--->234Th + 4He which is an alpha emission

at least thats what i think its supposed to be but here is my killer i dont understand what to do with something like this right here

3.) Protactinium-234 ---> Uranium-234 + _____

i dont know what to do with that hopefully some of you here may understand this cause im kind of lost here

[Coralis]

Here is my "guess" as it has been too long since Ive had to think along these lines:

You also have to factor in the atomic number of those elements

1) Uranium is 92 and Thorium is 90 so when you decay Uranium 238 to Thorium 234 you lose 2 protons (92 -90 = 2) and 2 neutrons which would be one alpha particle or Helium 4

2) Proactinium is 91 and Uranium is again 92 so you have a beta decay where a neutron is converted to a proton and electron, with the electron escaping

[DevilMan]

Oh I like chemistry....

That's not what you listed.... that's something from the back pages of a BDSM book...



No really... I can't help ya there... Hopefully some others can. I left off after High School, and I'm thinking that's NOT what this is....

DM

[michbich]

im lost and needing some guidence here

from what ive read this stuff is supposed to be basic stuff but i dont quite understand where the stuff is coming from

here are the instructions

"Uranium-238 decays through a serise of emissions of Alpha or Beta particles until it becomes lead-206. In the char below, fill in the missing particles and lablel the type of emission or each step.

1.) Uranium-238 ---> Thorium-234 + _____

now if im understanding since the uranium is heavy it looses 4 alpha particles, so the number 4 is atomic weight for helium so to balance this out its

238U--->234Th + 4He which is an alpha emission

at least thats what i think its supposed to be but here is my killer i dont understand what to do with something like this right here

3.) Protactinium-234 ---> Uranium-234 + _____

i dont know what to do with that hopefully some of you here may understand this cause im kind of lost here

1) It doesn't loose 4 alpha particles. It looses 1 alpha particle. An alpha particul is 2 neutrons and 2 protons.

The number 238 is equal to # protons + # of neutrons. Since the # of proton determines the element, it has no choice to loose 2 protons to deteriorate into Th. So that brings it to 236. This means that it needs to loose 2 neutrons to reach the mass of 234.

So 2 protons + 2 neutron is an helium atom = 1 alpha particle.

So it would be Th-234+He-4


2) i guess you skipped it lol


3) ok, i had to check on this one. A beta emission is the following reaction:

n ~\rightarrow~ p+e^-+\bar{\nu}_e

That little fancy equation simply means that you start with 1 neutron and end with 1 proton + 1 electron

N ----} P + E

So it would mean that Pa emitted a beta particle.

Pa 234 ----} U234 + 1electron

In conclusion:

1) emits 1 alpha particle

3)emits 1 Bet particle

[Dend78]

Here is my "guess" as it has been too long since Ive had to think along these lines:

You also have to factor in the atomic number of those elements

1) Uranium is 92 and Thorium is 90 so when you decay Uranium 238 to Thorium 234 you lose 2 protons (92 -90 = 2) and 2 neutrons which would be one alpha particle or Helium 4

2) Proactinium is 91 and Uranium is again 92 so you have a beta decay where a neutron is converted to a proton and electron, with the electron escaping

so how would i end up writing the answer to that? would it be something like this

234PA ---> 234U + 0/+1e?

[Dend78]

1) It doesn't loose 4 alpha particles. It looses 1 alpha particle. An alpha particul is 2 neutrons and 2 protons.

The number 238 is equal to # protons + # of neutrons. Since the # of proton determines the element, it has no choice to loose 2 protons to deteriorate into Th. So that brings it to 236. This means that it needs to loose 2 neutrons to reach the mass of 234.

So 2 protons + 2 neutron is an helium atom = 1 alpha particle.

So it would be Th-234+He-4


2) i guess you skipped it lol


3) Pa had to gain a proton and gain a neutron to change into U. Again, the most important part of an element is it's number of protons. Changing the number of protons will directly affect the element.

So Pa gained a proton and lost a neutron to transform into U to keep the 234 number. Are you sure it's the right number? Gaining a proton is actually hard work and is not a favorable reaction.

yeah i skipped 2 because i read it and thought it was almost like 1 but im wrong

2) Th-234 ---> Pa-234 + ______

this crap is crazy and its not even my homework its my wifes but i cant explain it to her cause i dont quite understand it either. im sorta on the brink of it but the book really doesnt explain it as i would like to see it.

[michbich]

I editted # 3 ^^

[michbich]

2) Th-234 ---> Pa-234 + ______


(90N) Th (234 N+P) ---} (91N) Pa (234 N+P)

Th gains 1 proton and looses 1 neutron since the # of proton is increased by 1 but the total amount (P+N) stays the same.

particle Beta: N --} P + E

it's basicly the same as #3.

I would say: Th-234 ----} Pa-234 + 1E

[Dend78]

hell yeah thats the way im seeing it from the way you are explaining it

so that lil e at the end is an electron i couldnt figure out what it was im like ok its not on the PT anywhere and im not 100% sure what it is but now i do believe i see it


thanks so much

[michbich]

I might not be the best in chem, but i can hold my own. Biochem...now that's another story.


Yes, the E is an electron.

Glad i could help. It's not easy trying to explain chem or science subjects in general on forums.

Again, the most important part in that work is to recognize the variation of protons for one side of the reaction to the other. When you figure that, you can figure the amount of neutron since neutron don't do anything special in the determination of the element except to modify the weight of the atom.

If you have other questions, don't hesitate. I like a good challenge that's not in my regular study path.

[Army]

"C"...it's always "C".