DP Physics (last assessment 2024)
Question 17N.2.SL.TZ0.2
| Date | November 2017 | Marks available | [Maximum mark: 4] | Reference code | 17N.2.SL.TZ0.2 |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Deduce, Distinguish | Question number | 2 | Adapted from | N/A |
2.
[Maximum mark: 4]
17N.2.SL.TZ0.2
The Feynman diagram shows electron capture.
(a)
Deduce that X must be an electron neutrino.
[2]
Markscheme
it has a lepton number of 1 «as lepton number is conserved»
it has a charge of zero/is neutral «as charge is conserved»
OR
it has a baryon number of 0 «as baryon number is conserved»
Do not credit answers referring to energy
(b)
Distinguish between hadrons and leptons.
[2]
Markscheme
hadrons experience strong force
OR
leptons do not experience the strong force
hadrons made of quarks/not fundamental
OR
leptons are not made of quarks/are fundamental
hadrons decay «eventually» into protons
OR
leptons do not decay into protons
Accept leptons experience the weak force
Allow “interaction” for “force”