Particles Definitions

Question 1

Isotope

Answer 1

atoms of the same element with the same number of protons (atomic number) but a different number of neutrons (mass number)

Question 2

Specific Charge Equation

Answer 2

charge / mass

Question 3

Specific Charge Units

Answer 3

Ckg^-1

Question 4

Particle with the greatest specific charge

Answer 4

electron (mass is extremely small Q/m)

Question 5

Alpha Radiation

Answer 5

Helium nucleus - 2 protons 2 neutrons
largest particle, slow-moving
can be stopped by paper - least penetrating a few cm in air
strongly ionising

Question 6

Beta Radiation

Answer 6

fast-moving electron
relative mass 0 relative charge -1
smallest particle
can be stopped by aluminium - relatively penetrating
less ionising than alpha

Question 7

Gamma Radiation

Answer 7

short wavelength, high frequency electromagnetic radiation
high energy photon, fast moving
has no mass, uncharged
most penetrating - long distances
can be stopped by lead
less ionising than alpha radiation

Question 8

Axes of a Feynmann Diagram

Answer 8

vertical - time
horizontal - space

Question 9

Funamental Forces and their Corresponding Exchange Particles

Answer 9

Strong force - pion
Weak force - W particle (boson)
Electromagnetic force - virtual photon
Gravitational force - graviton

Question 10

Pair Production

Answer 10

when a gamma photon changes into a particle and its corresponding antiparticle

Question 11

Annihilation

Answer 11

when a particle and its antiparticle meet, they destroy each other and releases 2 gamma photons

Question 12

Antimatter

Answer 12

particles with the same rest mass but equal and opposite charge as corresponding particle

Question 13

Exchange Particles Transfer…

Answer 13

momentum
energy
force
charge (only in weak interactions)

Question 14

Difference between Hadrons and Leptons

Answer 14

Hadrons feel the strong force
Leptons do not feel the strong force

Question 15

Baryon (protons, neutrons) Quark Composition

Answer 15

baryon qqq
protons uud neutrons dud

Question 16

Anti-Baryon (anti-proton, anti-neutron) Quark Composition

Answer 16

anti-baryon qqq

Question 17

Meson Quark Composition

Answer 17

meson qq (one antiquark one quark)

Question 18

What Baryons decay into

Answer 18

Protons

Question 19

Most stable Baryon

Answer 19

Proton

Question 20

What is conserved in strong and weak interactions?

Answer 20

All interactions : energy, momentum, charge, baryon number, lepton number

Strong force only : strangeness

Question 21

What is a Strange Particle

Answer 21

a particle that contains at least one strange quark or anti-quark

Question 22

Characteristics of a Strange Quark

Answer 22

has a strangeness of -1

Question 23

Size of Nucleus

Answer 23

x10^-15

Question 24

Size of Atom

Answer 24

x10^-10

Question 25

Properties of Strong Nuclear Force

Answer 25

Very short range force Repulsive: 0.5fm Attractive: between 0.5fm and 3fm Non existent: above 3fm

Question 26

Decay Modes of Unstable Nuclei

Answer 26

very large nuclei - alpha neutron rich nuclei - beta- proton rich nuclei - beta+ proton rich nuclei - electron capture

Question 27

Similarities between Hadrons and Leptons

Answer 27

They both feel the weak force and electromagnetic force (if they are charged).

Question 28

What do Kaons decay into

Answer 28

Pions

Question 29

What do Muons decay into

Answer 29

Electrons

Question 30

Properties of a Strange Particle

Answer 30

Strange particles are produced via strong interaction but decay via the weak interaction

Question 31

What is strangeness?

Answer 31

A quantum number to reflect the fact that strange particles are always created in pairs.

Question 32

In weak interactions, how does strangeness change?

Answer 32

Can change by -1, 0 or +1 in weak interactions.

Question 33

Conservation Rules for Weak Interaction

Answer 33

Baryon number, Charge and Lepton Number (by family) must all be conserved.

Question 34

Conservation Rules for Strong Interaction

Answer 34

Baryon number, Charge, Lepton Number (by family) and strangeness must all be conserved.