As part of his discovery of the neutron in $$1932$$, James Chadwick determined the mass of the neutron (newly$$ identified $$particle) by firing a beam of fast neutrons all having the same speed, as two different targets and measuring the maximum recoil speeds of the target nuclei. The maximum speed arises when an elastic $$head-on$$ collision occurs between a neutron and a stationary target nucleus. Represent the masses and final speeds of the two target nuclei as $$m1$$, $$v1$$, $$m2$$ and $$v2$$ and assume Newtonian mechanics applies. The neutron mass can be calculated from the equation $$mn=m1v1$$−$$m2v2v2$$−$$v1Chadwick$$ directed a beam of neutrons on paraffin, which contains hydrogen. The maximum speed of the protons ejected was found to be $$3.3$$×$$107m/s$$ A second experiment was performed using neutrons from the same source and nitrogen nuclei as the target. The maximum recoil speed of the nitrogen nuclei was found to be $$4.7$$×$$106m/s$$. The masses of a proton and a nitrogen were taken as $$1$$ u and $$14u$$, respectively. What was Chadwick’s value for the neutron mass?

Question

As part of his discovery of the neutron in $$1932$$, James Chadwick determined the mass of the neutron (newly$$ identified $$particle) by firing a beam of fast neutrons all having the same speed, as two different targets and measuring the maximum recoil speeds of the target nuclei. The maximum speed arises when an elastic $$head-on$$ collision occurs between a neutron and a stationary target nucleus. Represent the masses and final speeds of the two target nuclei as  $$m1$$, $$v1$$, $$m2$$ and $$v2$$ and assume Newtonian mechanics applies. The neutron mass can be calculated from the equation $$mn=m1v1$$−$$m2v2v2$$−$$v1Chadwick$$ directed a beam of neutrons on paraffin, which contains hydrogen. The maximum speed of the protons ejected was found to be $$3.3$$×$$107m/s$$ A second experiment was performed using neutrons from the same source and nitrogen nuclei as the target. The maximum recoil speed of the nitrogen nuclei was found to be $$4.7$$×$$106m/s$$. The masses of a proton and a nitrogen were taken as $$1$$ u and $$14u$$, respectively. What was Chadwick’s value for the neutron mass?

Infinity Learn · Accepted Answer

[ Concept ]:$$mn=m1v1$$−$$m2v2v2$$−$$v1$$[ Step $$1$$]:$$=14$$×$$4.7$$×$$106$$−$$1$$×$$3.3$$×$$1073.3$$×$$107$$−$$4.7$$×$$106=1.16$$

Best Courses for You

Detailed Solution

courses

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

download the app

Download the App