quarks

Question 1

Rules

Answer 1

• baryons are made of 3 quarks
• antibaryons are made of 3 anitquarks
• mesons are made from a quark and antiquark

Question 2

Properties

Answer 2

type, charge, baryon number, strangeness

u: +2/3, +1/3, 0
d: -1/3, +1/3, 0
s: -1/3, +1/3, -1

Question 3

Proton

Answer 3

uud

• charge= 2/3 + 2/3 + (-1/3) = 1
• baryon number= 1/3 + 1/3 + 1/3 = 1
• strangeness= 0

Question 4

Neutron

Answer 4

udd

• chrage= 2/3 + (-1/3) + (-1/3) = 0
• baryon number= 1/3 + 1/3 + 1/3 = 1
• strangeness= 0

Question 5

Antiproton

Answer 5

ūūđ

• charge= (-2/3) + (-2/3) + 1/3 = -1
• baryon number= (-1/3) +(-1/3) + (-1/3) = -1
• strangeness= 0

Question 6

Positive Pion

Answer 6

uđ

• charge= 2/3 + 1/3 = 1
• baryon number= 1/3 + (-1/3) = 0
• strangeness= 0

Question 7

Positive Kaon

Answer 7

us-

• charge= 2/3 + 1/3 = 1
• baryon number= 1/3 + (-1/3) = 0
• strangeness= 1

Question 8

Weak interaction

Answer 8

involves a change in quark
n --> p + e- + v-
n=udd p=uud
- so a down quark turns into an up quark 
d --> u + e- + v-