Q7 · 2024 · Paper 2Simple familiar4 marks
QUESTION 7 (4 marks)
a)[2 marks]
Contrast baryons and mesons in terms of composition.
b)[2 marks]
Contrast quarks and leptons in terms of the possible fundamental forces they experience.
WORKED SOLUTION
4 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
Baryons are composed of three quarks. Whereas mesons are
composed of one quark and one antiquark.
Quarks experience all four fundamental forces (strong nuclear
force, weak nuclear force, electromagnetic force and
gravitational force).
Whereas leptons experience only the weak nuclear force,
gravitational force and electromagnetic force (if they have a
charge).
• identifies baryons are composed of
3 quarks [1 mark]
• identifies mesons are composed of
1 quark and 1 antiquark [1 mark]
• recognises quarks experience all
forces whereas leptons do not
experience the strong nuclear force
[1 mark]
• identifies that only charged leptons
would experience electromagnetic
force [1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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