Particle Physics

Question 1

How is Rutherford’s Scattering experiment conducted?

Answer 1

beam of alpha particles from a radioactive source were targeted towards a thin gold foil

Question 2

Rutherford’s: Most alpha particles went straight through the gold foil, what does this show?

Answer 2

gold atoms were mostly emptty space

Question 3

Rutherford’s: Some alpha particles were scattered at angles greater than 90 degrees, what does this show?

Answer 3

each gold atom has a positive nucleus with a radius less than about 10^-14m

Question 4

Rutherford’s: What is the scattering of alpha due to?

Answer 4

electrostatic repulsion by the gold nucleus

Question 5

What is the nucleus made up from?

Answer 5

neutrons and protons

Question 6

What is a nucleon?

Answer 6

neutron or proton

Question 7

What is the nucleus surrounded by?

Answer 7

cloud of electrons

Question 8

What is equal in a neutral atom?

Answer 8

number of protons and electrons

Question 9

How do you calculate the number of neutrons in an atom?

Answer 9

nucleon number - proton/atomic number

Question 10

What is an isotope?

Answer 10

nuclei of the same element that have the same number of protons but different number of neutrons

Question 11

What is the mass of a particle quoted in?

Answer 11

atomic mass units (u)

Question 12

How much smaller is the volume of the nucleus than the volume of the atom?

Answer 12

10^15

Question 13

Why is the mass of the atom approximately the same as the mass of the nucleus?

Answer 13

minuscule mass of electrons

Question 14

What forces do protons within a nucleus experience?

Answer 14

large electrostatic repulsive forces

Question 15

What force do all nucleons inside the nucleus experience?

Answer 15

strong nuclear force

Question 16

When is nuclear force attractive?

Answer 16

up to 3fm

Question 17

When is nuclear force repulsive?

Answer 17

below 0.5fm

Question 18

What is the antiparticle of an electron?

Answer 18

positron

Question 19

What is the antiparticle of a proton?

Answer 19

antiproton

Question 20

What is the antiparticle of a neutron?

Answer 20

antineutron

Question 21

What is the antiparticle of a neutrino?

Answer 21

antineutrino

Question 22

What are fundamental particles?

Answer 22

no internal structure so cannot be divided into smaller particles

Question 23

What are examples of fundamental particles?

Answer 23

electrons and quarks

Question 24

What are protons and neutrons not fundamental particles?

Answer 24

made up of quarks

Question 25

What are hadrons?

Answer 25

particles and antiparticles that are affected by strong nuclear force

Question 26

How do hadrons decay?

Answer 26

weak nuclear force

Question 27

What are the 4 hadrons?

Answer 27

protons, neutrons, baryons, mesons

Question 28

What are leptons?

Answer 28

particles and antiparticles that are not affected by strong nuclear force

Question 29

What are the 3 leptons?

Answer 29

electrons, neutrinos, muons

Question 30

What force do both hadrons and leptons experience?

Answer 30

electromagnetic force

Question 31

What are the 4 fundamental forces?

Answer 31

strong nuclear, electromagnetic, weak nuclear, gravitational

Question 32

What is any particle made up of quarks called?

Answer 32

hadron

Question 33

How many quarks does a standard particle of elementary charge require?

Answer 33

6

Question 34

What are the 6 quarks?

Answer 34

up, down, strange, anti-up, anti-down, anti-strange

Question 35

What is the quark make up of a proton?

Answer 35

U U D + e

Question 36

What is the quark make up of a neutron?

Answer 36

U D D

Question 37

Define radioactivity:

Answer 37

decay of an unstable nucleus

Question 38

Which types of nuclei decay by emitting beta radiation?

Answer 38

beta plus and beta minus

Question 39

What type of particles have negligible mass and no charge?

Answer 39

neutrinos

Question 40

What is the make up of beta minus decay?

Answer 40

Neutron > proton + electron + electron antineutrino

Question 41

What quark changes in beta minus decay?

Answer 41

down > up

Question 42

What is the make up of beta plus decay?

Answer 42

proton > neutron + positron + electron neutrino

Question 43

What quark changes in beta plus decay?

Answer 43

up > down

Question 44

What is the nature of alpha?

Answer 44

helium nucleus

Question 45

What is the nature of beta?

Answer 45

electron

Question 46

What is the nature of gamma?

Answer 46

electromagnetic radiation (wave)

Question 47

What is the range of alpha in air?

Answer 47

few cm

Question 48

What is the range of beta in air?

Answer 48

about 1m

Question 49

What is the range of gamma in air?

Answer 49

several km

Question 50

What is the penetration ability of alpha?

Answer 50

0.2mm paper

Question 51

What is the penetration ability of beta?

Answer 51

1-10 mm of aluminium

Question 52

What is the penetration ability of gamma?

Answer 52

several m concrete