Particle Physics

Question 1

Annihilation

Answer 1

particle n antiparticle colliding and being converted to energy. energy release in 2 photons to conserver energy

Question 2

Antiparticle

Answer 2

all particles have antiparticle with same mass but opposite charge n conservation numbers.

Question 3

Baryon number

Answer 3

conserved in all particle interactions. baryons have B=+1 and non baryons B = 0

Question 4

Baryon.

Answer 4

Class of hardon, 3 quarks. Proton = only stable baryon

Question 5

B-

Answer 5

neutrin inside nucleus -> proton, emits B- parrticle n antineutrino

Question 6

B+

Answer 6

proton inside nucleus -> neutron, emits B+ particle n neutrino

Question 7

electron diffraction

Answer 7

spreading of electrons as they pass through a gap similar to magnitude of their de brog wavelength. It’s evidence of the wave-like properties of particles.

Question 8

eV

Answer 8

work done to accelerate electron through pd of 1V. E=qv

Question 9

Energy levels

Answer 9

energies which electrons can exist in an atom. electrons cannot exist between these levels

Question 10

Excitation

Answer 10

process of electron taking in exactly the right quantity of energy to move it to higher level

Question 11

gauge boson

Answer 11

exchange particles that transmit 4 fundamental interactions between particles

Question 12

ground state

Answer 12

most stable energy level an electron can exist in

Question 13

Hadrons

Answer 13

Class of subatomic particle that experiences strong force.

Question 14

Ionisation

Answer 14

process of atom losing an electron n becoming charged.

Question 15

kaon

Answer 15

type of meson that decays into pions

Question 16

lepton number

Answer 16

quantum number that is conserved in all interactions. both electron lepton no n muon lepton no must be conserved.

Question 17

lepton

Answer 17

group of subatomic particles consisting of electrons, muons,and neutrinos

Question 18

meson

Answer 18

clas of hardon made of quark, anti quark

Question 19

muon

Answer 19

type of lepton that decays into electron

Question 20

neutrino

Answer 20

subatomic particle whose existence is hypothesised to maintain conservation of energy in beta decay

Question 21

nucleon

Answer 21

proton or neutron

Question 22

pair production

Answer 22

process of sufficiently high energy photon converting into particle and antiparticle. to converse momentum, usually occurs near nucleus

Question 23

photon

Answer 23

packet of energy

Question 24

pion

Answer 24

type of meson n exchange particle for strong force.

Question 25

positron

Answer 25

+ve charged. antiparticle of electron

Question 26

stopping potential

Answer 26

minimum PD required to stop the highest KE electrons from leaving metal plate in Photoelectric effect.

Question 27

Strange particles

Answer 27

particles produced through strong interaction but decay through weak interaction

Question 28

strangeness

Answer 28

quantum number conserved in strong interactions but not in weak. reflects that strange particles always produced in pairs

Question 29

strong force

Answer 29

force acts between nucleons to keep it stable. Attractive up to 3fm and Repulsive at <0.5fm

Question 30

threshold frequency

Answer 30

min frequency required of photons for photoelectrons to be emitted from surface of metal plate through photoelectric effect. is equal to metals work function divided by plancks constant

Question 31

work function

Answer 31

min energy required to move electron from metals surface