Question

How do i calculate the number of neutrons in uranium when i have 92 protons and a specific charge of 3.7*10^7?

Answer 1

no of protons = no of electron and no of neutrons = no of electrons + no of protons.

Answer 2

so we know the specific charge = (3.7x10^7) so we know the charge is 92(1.6 X10^-19)/ mass which is (92+x)(1.67 x10^-27)

so we put mass on oneside and numericals on the other to get:
(92 + X) (1.67x10^-27)=3.97x10^-25 3.97..... is (92(1.6x10^-19)) / (3.7x10^7)

divide it out 92 + x = 238 ish

x = 238-92
X= 146

http://www.thestudentroom.co.uk/showthread.php?t=1282309 (jclark_76)

Answer 3

units of specific charge = charge / unit mass

Answer 4

yes that is correct

Answer 5

Where do i get x from?

Answer 6

x stands for the number of neutrons

Answer 7

Ok so i have done the calculations and i have 3.97*10^-25. How do i calculate the 238 for the number of neutrons?

Answer 8

what are the units of that number

Answer 9

3.97*10^-25 = (92(1.6x10^-19)) / (3.7x10^7)

Answer 10

How do you come to the answer of 238?

Answer 11

Can you explain how we come to 238 brent0423?

Answer 12

http://www.hobart.k12.in.us/ksms/PeriodicTable/uranium.htm

Answer 13

Yes i know that but how do you go from this calculation 3.97*10^-25 = (92(1.6x10^-19)) / (3.7x10^7) to X = 238 ?

Answer 14

How do we arrive at x= 238? When all i have is3.97*10^-25 ?

Answer 15

Am i missing a calculation or is there more to add?

Answer 16

\[x\neq 238\]
it is very hard to see what you are doing when you don't have units floating around

Answer 17

Its ok posting threads to different sites for the answers but if you cannot explain the answer of how we arrive at 238 from this 3.97*10^-25 = (92(1.6x10^-19)) / (3.7x10^7) to X = 238 i have given all the units!

Answer 18

(1.67 x10^-27)

so we put mass on oneside and numericals on the other to get:
(92 + X) (1.67x10^-27)=3.97x10^-25 3.97..... is (92(1.6x10^-19)) / (3.7x10^7)

divide it out 92 + x = 238 ish

Where do i get X = 238 ?

Answer 19

wait one minute and i will provide a step by step solution

Answer 20

Ok thankyou

Answer 21

no worries, im sorry that the link i provided was misleading

Answer 22

Its ok i just need a better explanation

Answer 23

protons plus neutrons equals 238

so if you have 92 protons you would have to have 146 neutrons

Answer 24

Yes i know but there are two types of uranium 235 & 238 so how would i know which one to choose?